From addab4016eabfff98d62c383b1ddecdf6c4f3373 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 13:51:43 +0000
Subject: [PATCH 1/9] feat(pathfinder): query current prepared endpoints
 without fallback

---
 .github/workflows/ci.yml                |  2 +-
 rfc/prepared-endpoint-implementation.md | 29 ++++++++
 src/nav/controller.zig                  | 94 +++++++++++++++++++++++++
 tests/integration/preparation_test.zig  | 77 ++++++++++++++++++++
 4 files changed, 201 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 76a3586..451047a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -33,7 +33,7 @@ jobs:
         run: |
           git init ../labelle-engine
           git -C ../labelle-engine remote add origin https://github.com/labelle-toolkit/labelle-engine.git
-          git -C ../labelle-engine fetch --depth 1 origin b93dafd1295fe5324be70c6249fc4687a78b8fe3
+          git -C ../labelle-engine fetch --depth 1 origin 58c060d227f614b8476836b6d74b163a9be4f53d
           git -C ../labelle-engine checkout --detach FETCH_HEAD
 
       - name: Run engine integration tests
diff --git a/rfc/prepared-endpoint-implementation.md b/rfc/prepared-endpoint-implementation.md
index 1d9b570..3edb4b1 100644
--- a/rfc/prepared-endpoint-implementation.md
+++ b/rfc/prepared-endpoint-implementation.md
@@ -148,3 +148,32 @@ mutation and participant audits, generation-qualified graph/query freshness,
 remaining CMN writers/known-node updates, frame-order placement, game query migration
 and normal-retry handling for active jobs/raids. In particular, this phase's graph
 checks do not constitute a query-time guarantee after arbitrary later mutations.
+
+## Prepared queries and graph dependency freshness
+
+`preparedDistance(game, from, to)` reads only current published endpoints and the
+existing FW table. Ordinary entities require a ready CMN with matching world,
+entity, position and graph stamps. MovementNode endpoints use the current live
+entity registration directly, without a self-CMN. A stale/absent/off-graph or
+disconnected endpoint, dirty table, or changed graph dependency returns null.
+There are no allocations, parent walks, nearest-node scans, repairs or Euclidean
+fallbacks in this query.
+
+Graph construction watches MovementNode/MovementStair/MovementLink mutations and
+registered node positions through the engine dependency group. Any subsequent
+watched mutation invalidates all prepared queries immediately. Full graph input
+validation remains in advance/preparation, outside queries. Direct backend writes
+must use the engine invalidation companion; command-level node removal also
+invalidates the table. Component-pointer writes are not magically observable.
+
+`endpointPreparationComplete` is a separate lifecycle gate: pending/stale is
+false, completed off-graph is true. It does not change the matching null contract.
+It lets an active job or raid retry preparation before concluding that no usable
+candidate exists. Destroyed targets still need the consumer's existing lifetime
+policy.
+
+`publishKnownEndpoint` supports explicit docking/placement. It validates actual
+world-space position against the registered node, snap radius and Y filter, then
+publishes the current stamp. It rejects MovementNode recipients and cannot repair
+a stale graph. Opted-in `requestRepath` invalidates for the bounded phase instead
+of scanning synchronously. Legacy navigation commands remain available separately.
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index 486a630..69f81f6 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -223,6 +223,7 @@ pub const State = struct {
     pf: Pf,
     preparation_world: u64,
     preparation_enabled: bool = false,
+    graph_dependency_revision: ?u64 = null,
     preparation_in_flight: bool = false,
     preparation_stats: PreparationStats = .{},
     preparation_batch: @import("preparation_batch.zig").PreparationBatch = .{},
@@ -770,6 +771,77 @@ pub const Controller = struct {
         return st.graph_epoch;
     }
 
+    /// Pure prepared matching: no world-position reads, nearest-node search,
+    /// allocation, table rebuild, or fallback. All nonmatches return null.
+    pub fn preparedDistance(game: anytype, from_entity: anytype, to_entity: anytype) ?f32 {
+        const st = findState(game) orelse return null;
+        if (!preparedGraphCurrent(game, st)) return null;
+        const from = preparedEndpointNode(game, st, from_entity) orelse return null;
+        const to = preparedEndpointNode(game, st, to_entity) orelse return null;
+        return st.pf.preparedNodeDistance(from, to);
+    }
+
+    /// Publish a known placement (for example a ship's docking node). This
+    /// command validates the actual world-space position; it never scans for
+    /// another node and never attaches a CMN to a MovementNode.
+    pub fn publishKnownEndpoint(game: anytype, entity: anytype, node_entity: anytype) !bool {
+        const st = findState(game) orelse return false;
+        if (!preparedGraphCurrent(game, st)) return false;
+        const ecs = &game.active_world.ecs_backend;
+        if (!ecs.entityExists(entity) or ecs.hasComponent(entity, MovementNode)) return false;
+        const node = registeredNode(game, st, node_entity) orelse return false;
+        const pos = game.getWorldPosition(entity);
+        const anchor = st.pf.graph.getPosition(node);
+        const dx = pos.x - anchor.x;
+        const dy = pos.y - anchor.y;
+        const distance_to_node = @sqrt(dx * dx + dy * dy);
+        if (!std.math.isFinite(distance_to_node) or distance_to_node > MAX_NODE_SNAP_DISTANCE or anchor.y > pos.y + Y_FILTER_EPS) return false;
+        _ = try game.trackPositionRevision(entity);
+        const stamp = endpointStamp(game, st, entity) orelse return false;
+        var cmn = if (ecs.getComponent(entity, ClosestMovementNode)) |old| old.* else ClosestMovementNode{};
+        if (!cmn.publish(stamp, stamp, .{ .node_entity = @intCast(node_entity), .node_id = node, .distance = distance_to_node })) return false;
+        ecs.addComponent(entity, cmn);
+        return true;
+    }
+
+    /// Lifecycle gate, separate from matching: false means retry preparation
+    /// before concluding that an active job/raid has no reachable candidates.
+    /// Off-graph is a completed result, while pending/stale is not.
+    pub fn endpointPreparationComplete(game: anytype, entity: anytype) bool {
+        const st = findState(game) orelse return false;
+        if (!preparedGraphCurrent(game, st)) return false;
+        const ecs = &game.active_world.ecs_backend;
+        if (!ecs.entityExists(entity)) return false;
+        if (ecs.hasComponent(entity, MovementNode)) return preparedEndpointNode(game, st, entity) != null;
+        const cmn = ecs.getComponent(entity, ClosestMovementNode) orelse return false;
+        return cmn.current(endpointStamp(game, st, entity) orelse return false);
+    }
+
+    fn preparedGraphCurrent(game: anytype, st: *State) bool {
+        const revision = st.graph_dependency_revision orelse return false;
+        return st.preparation_enabled and st.nodes_registered and
+            revision == game.dependencyRevision() and !st.pf.graph.dirty and st.pf.fw != null;
+    }
+
+    fn registeredNode(game: anytype, st: *State, entity: anytype) ?NodeId {
+        const ecs = &game.active_world.ecs_backend;
+        if (!ecs.entityExists(entity)) return null;
+        const node = ecs.getComponent(entity, MovementNode) orelse return null;
+        if (st.node_entities.get(node.node_id) != @as(u64, @intCast(entity)) or st.pf.graph.isRemoved(node.node_id)) return null;
+        return node.node_id;
+    }
+
+    fn preparedEndpointNode(game: anytype, st: *State, entity: anytype) ?NodeId {
+        const ecs = &game.active_world.ecs_backend;
+        if (!ecs.entityExists(entity)) return null;
+        if (ecs.hasComponent(entity, MovementNode)) return registeredNode(game, st, entity);
+        const cmn = ecs.getComponent(entity, ClosestMovementNode) orelse return null;
+        if (!cmn.ready(endpointStamp(game, st, entity) orelse return null)) return null;
+        const node = registeredNode(game, st, @as(@TypeOf(entity), @intCast(cmn.node_entity))) orelse return null;
+        if (node != cmn.node_id) return null;
+        return node;
+    }
+
     /// Graph path-length between two game entities, via each entity's
     /// nearest movement node. Returns `null` when the controller isn't
     /// set up, either entity has no nearby node (Y-filtered, see
@@ -1037,6 +1109,10 @@ pub const Controller = struct {
         const st = findState(game) orelse return;
         const entity_id: u64 = @intCast(entity);
         const ecs = &game.active_world.ecs_backend;
+        if (st.preparation_enabled) {
+            if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| cmn.invalidate(.position);
+            return;
+        }
         const pos = game.getWorldPosition(entity);
         if (findNearestNodeForEntity(st, entity_id, pos.x, pos.y)) |nid| {
             const node_pos = st.pf.graph.getPosition(nid);
@@ -1242,6 +1318,7 @@ pub const Controller = struct {
     /// actual ECS inputs, including ancestor movement and authored edge edits.
     fn graphInputsCurrent(game: anytype, st: *State) bool {
         if (!st.nodes_registered or st.graph_epoch == 0) return false;
+        if (st.graph_dependency_revision == null or st.graph_dependency_revision.? != game.dependencyRevision()) return false;
         if (st.graph_inputs.count() != st.node_entities.count()) return false;
         const ecs = &game.active_world.ecs_backend;
         var view = ecs.view(.{MovementNode}, .{});
@@ -1344,10 +1421,26 @@ pub const Controller = struct {
 
     fn buildGraphIntoState(game: anytype, st: *State) void {
         const ecs = &game.active_world.ecs_backend;
+        st.graph_dependency_revision = null;
+        var watches_ok = st.preparation_enabled;
+        if (st.preparation_enabled) {
+            game.watchComponentDependency(MovementNode) catch {
+                watches_ok = false;
+            };
+            game.watchComponentDependency(MovementStair) catch {
+                watches_ok = false;
+            };
+            game.watchComponentDependency(MovementLink) catch {
+                watches_ok = false;
+            };
+        }
         var view = ecs.view(.{MovementNode}, .{});
         defer view.deinit();
 
         while (view.next()) |entity| {
+            if (st.preparation_enabled) game.watchPositionDependency(entity) catch {
+                watches_ok = false;
+            };
             // World position, not local: movement nodes declared
             // inside a room prefab (`Room.movement_nodes`) end up as
             // children of the room entity, so `getPosition` returns
@@ -1390,6 +1483,7 @@ pub const Controller = struct {
         linkAuthoredEdges(game, st);
 
         st.nodes_registered = st.node_entities.count() > 0;
+        if (watches_ok) st.graph_dependency_revision = game.dependencyRevision();
         if (st.nodes_registered) {
             log.info("graph built: {d} nodes (Floyd-Warshall)", .{st.node_entities.count()});
         }
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index d2eaf3b..a6be232 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -280,3 +280,80 @@ test "legacy targetPosition never treats off-graph debugging data as a ready nod
     try testing.expectEqual(old.node_entity, off_graph.node_entity);
     try testing.expectEqualDeep(game.getWorldPosition(e), C.targetPosition(&game, e));
 }
+
+test "prepared matching rejects stale endpoints and graph inputs without repairing them" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const n2 = node(&game, 50);
+    const a = item(&game, 1);
+    const b = item(&game, 51);
+    try setup(&game);
+    defer C.deinit(&game);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+    _ = try run(&game, 8);
+    try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, a, b));
+    try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, n, n2));
+    try testing.expect(!game.hasComponent(n, CMN));
+    const old = game.getComponent(a, CMN).?.*;
+    game.setPosition(a, .{ .x = 2 });
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+    try testing.expect(!C.endpointPreparationComplete(&game, a));
+    try testing.expectEqualDeep(old, game.getComponent(a, CMN).?.*);
+    _ = try run(&game, 8);
+    try testing.expect(C.endpointPreparationComplete(&game, a));
+    game.setPosition(n2, .{ .x = 60 });
+    // Even a query involving only the unchanged node must reject the graph.
+    try testing.expectEqual(null, C.preparedDistance(&game, n, n));
+    C.advance(&game, 0);
+    _ = try run(&game, 8);
+    try testing.expectEqual(@as(?f32, 60), C.preparedDistance(&game, a, b));
+    game.addComponent(n, pf.MovementStair{});
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+    C.advance(&game, 0);
+    _ = try run(&game, 8);
+    _ = node(&game, 75);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+}
+
+test "off-graph is complete but never a match; missing controller never falls back" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const a = item(&game, 0);
+    const b = item(&game, 10000);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, a));
+    _ = node(&game, 0);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try run(&game, 8);
+    try testing.expect(C.endpointPreparationComplete(&game, b));
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+    try testing.expectEqual(null, C.preparedDistance(&game, b, b));
+}
+
+test "known docking placement validates world geometry and is invalidated by ancestry" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const dock = node(&game, 0);
+    const other = node(&game, 500);
+    const parent = game.createEntity();
+    const bandit = item(&game, 1);
+    game.setParent(bandit, parent, .{});
+    try testing.expect(!try C.publishKnownEndpoint(&game, bandit, dock));
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try run(&game, 8);
+    try testing.expect(try C.publishKnownEndpoint(&game, bandit, dock));
+    try testing.expectEqual(@as(?f32, 0), C.preparedDistance(&game, bandit, dock));
+    try testing.expectEqual(null, C.preparedDistance(&game, bandit, other));
+    try testing.expect(!try C.publishKnownEndpoint(&game, bandit, other));
+    try testing.expect(!try C.publishKnownEndpoint(&game, dock, dock));
+    game.setPosition(parent, .{ .x = 5 });
+    try testing.expectEqual(null, C.preparedDistance(&game, bandit, dock));
+    try testing.expect(try C.publishKnownEndpoint(&game, bandit, dock));
+    game.setPosition(parent, .{ .y = -10 }); // anchor is above the allowed Y filter
+    try testing.expect(!try C.publishKnownEndpoint(&game, bandit, dock));
+    try testing.expectEqual(null, C.preparedDistance(&game, bandit, dock));
+    game.setPosition(parent, .{ .x = 1000 });
+    try testing.expect(!try C.publishKnownEndpoint(&game, bandit, dock));
+}

From c4be09a50a062097f45eb284405e6c26d762080c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 13:57:57 +0000
Subject: [PATCH 2/9] test(pathfinder): cover deferred explicit repath

---
 tests/integration/preparation_test.zig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index a6be232..823ed82 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -294,6 +294,11 @@ test "prepared matching rejects stale endpoints and graph inputs without repairi
     _ = try run(&game, 8);
     try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, a, b));
     try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, n, n2));
+    C.requestRepath(&game, a);
+    try testing.expectEqual(CMN.Status.pending, game.getComponent(a, CMN).?.status);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, b));
+    _ = try run(&game, 8);
+    try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, a, b));
     try testing.expect(!game.hasComponent(n, CMN));
     const old = game.getComponent(a, CMN).?.*;
     game.setPosition(a, .{ .x = 2 });

From 0c9ed78b5133286b01846ce3ac7b715e75429b99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 16:05:38 +0000
Subject: [PATCH 3/9] fix(pathfinder): avoid unsupported wasm32 world identity
 atomic

---
 .github/workflows/ci.yml          |  3 +++
 build.zig                         | 31 +++++++++++++++++++++++++++++++
 src/nav/controller.zig            | 11 +++++++----
 tests/wasm/controller_compile.zig | 13 +++++++++++++
 4 files changed, 54 insertions(+), 4 deletions(-)
 create mode 100644 tests/wasm/controller_compile.zig

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 451047a..b636497 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,6 +27,9 @@ jobs:
       - name: Run zspec tests
         run: zig build spec
 
+      - name: Compile controller for wasm32
+        run: zig build wasm-check
+
       # Prepared endpoint integration depends on engine#916 until its release.
       # Pin the exact tested commit rather than following an unreleased branch.
       - name: Checkout engine position revision API
diff --git a/build.zig b/build.zig
index e98b05f..5d27245 100644
--- a/build.zig
+++ b/build.zig
@@ -74,4 +74,35 @@ pub fn build(b: *std.Build) void {
 
     const spec_step = b.step("spec", "Run zspec navigation tests");
     spec_step.dependOn(&run_nav_tests.step);
+
+    // Force controller lifecycle code generation for the threaded web target.
+    // This catches unsupported atomics without requiring the Emscripten SDK.
+    const wasm_target = b.resolveTargetQuery(.{
+        .cpu_arch = .wasm32,
+        .os_tag = .freestanding,
+        .cpu_features_add = std.Target.wasm.featureSet(&.{ .atomics, .bulk_memory }),
+    });
+    const wasm_core = b.dependency("labelle_core", .{
+        .target = wasm_target,
+        .optimize = .ReleaseSmall,
+    }).module("labelle-core");
+    const wasm_pathfinder = b.createModule(.{
+        .root_source_file = b.path("src/root.zig"),
+        .target = wasm_target,
+        .optimize = .ReleaseSmall,
+        .imports = &.{
+            .{ .name = "zig_utils", .module = zig_utils },
+            .{ .name = "labelle-core", .module = wasm_core },
+        },
+    });
+    const wasm_controller = b.addObject(.{
+        .name = "wasm-controller-check",
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("tests/wasm/controller_compile.zig"),
+            .target = wasm_target,
+            .optimize = .ReleaseSmall,
+            .imports = &.{.{ .name = "pathfinder", .module = wasm_pathfinder }},
+        }),
+    });
+    b.step("wasm-check", "Compile controller lifecycle for wasm32").dependOn(&wasm_controller.step);
 }
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index 69f81f6..46b2ced 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -209,11 +209,14 @@ const EndpointSnapshot = struct {
 };
 // Identity only: never used for selection order. A fresh controller lifetime
 // cannot accept publication metadata from an old world, even at the same address.
-var next_preparation_world = std.atomic.Value(u64).init(0);
+// Controller lifetimes are created/destroyed on the simulation thread. Future
+// preparation workers consume snapshots; they must not construct controller state.
+// Keep the full u64 identity range without requiring unsupported wasm32 atomics.
+var next_preparation_world: u64 = 0;
 fn newPreparationWorld() u64 {
-    const previous = next_preparation_world.fetchAdd(1, .monotonic);
-    if (previous == std.math.maxInt(u64)) @panic("preparation world identity exhausted");
-    return previous + 1;
+    if (next_preparation_world == std.math.maxInt(u64)) @panic("preparation world identity exhausted");
+    next_preparation_world += 1;
+    return next_preparation_world;
 }
 
 /// Heap-allocated runtime state. Not exported directly — callers reach
diff --git a/tests/wasm/controller_compile.zig b/tests/wasm/controller_compile.zig
new file mode 100644
index 0000000..9716d5f
--- /dev/null
+++ b/tests/wasm/controller_compile.zig
@@ -0,0 +1,13 @@
+//! Compile the real controller lifecycle for wasm32. No browser or SDK needed.
+//! Exporting the identity forces code generation for State.init, unlike decl-only
+//! checks which missed the unsupported u64 atomic in the preparation counter.
+const std = @import("std");
+const pathfinder = @import("pathfinder");
+
+export fn preparationWorldIdentity() u64 {
+    var memory: [32768]u8 = undefined;
+    var allocator = std.heap.FixedBufferAllocator.init(&memory);
+    var state = pathfinder.controller.State.init(allocator.allocator());
+    defer state.deinit();
+    return state.preparation_world;
+}

From d11e29750d4cd8bffc9fe800f715e3980506fc26 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 16:27:06 +0000
Subject: [PATCH 4/9] perf(pathfinder): reuse certified nearest nodes during
 preparation

---
 .github/workflows/ci.yml               |   4 +-
 src/nav/components.zig                 |  16 ++-
 src/nav/controller.zig                 | 133 +++++++++++++++++++++----
 tests/integration/preparation_test.zig |  85 ++++++++++++++++
 tests/nav/prepared_endpoint_test.zig   |   2 +-
 5 files changed, 218 insertions(+), 22 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b636497..9f39bf1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,13 +30,13 @@ jobs:
       - name: Compile controller for wasm32
         run: zig build wasm-check
 
-      # Prepared endpoint integration depends on engine#916 until its release.
+      # Prepared endpoint integration depends on engine#917 until its release.
       # Pin the exact tested commit rather than following an unreleased branch.
       - name: Checkout engine position revision API
         run: |
           git init ../labelle-engine
           git -C ../labelle-engine remote add origin https://github.com/labelle-toolkit/labelle-engine.git
-          git -C ../labelle-engine fetch --depth 1 origin 58c060d227f614b8476836b6d74b163a9be4f53d
+          git -C ../labelle-engine fetch --depth 1 origin c9dddffba8f78d9e1dbd5a81d34f5623b669a2e5
           git -C ../labelle-engine checkout --detach FETCH_HEAD
 
       - name: Run engine integration tests
diff --git a/src/nav/components.zig b/src/nav/components.zig
index 9603ec9..32e384e 100644
--- a/src/nav/components.zig
+++ b/src/nav/components.zig
@@ -51,6 +51,7 @@ pub const ClosestMovementNode = struct {
         entity_id: u64 = 0,
         entity_generation: u64 = 0,
         position_revision: u64 = 0,
+        position_slot: u32 = @import("std").math.maxInt(u32),
         graph_revision: u64 = 0,
 
         pub fn valid(self: Stamp) bool {
@@ -59,16 +60,26 @@ pub const ClosestMovementNode = struct {
 
         pub fn eql(a: Stamp, b: Stamp) bool {
             return a.world_revision == b.world_revision and a.entity_id == b.entity_id and a.entity_generation == b.entity_generation and
-                a.position_revision == b.position_revision and a.graph_revision == b.graph_revision;
+                a.position_revision == b.position_revision and a.position_slot == b.position_slot and a.graph_revision == b.graph_revision;
         }
     };
     pub const Status = enum { pending, ready, off_graph };
     pub const Invalidation = enum { none, position, ancestor, parent, graph, world };
-    pub const Resolution = struct { node_entity: u64, node_id: u32, distance: f32 };
+    /// Conservative nearest-node certificate, created only by full preparation.
+    /// It stays centred at the original sample even across repeated reuse.
+    pub const ReuseRegion = struct {
+        x: f32 = 0,
+        y: f32 = 0,
+        radius: f64 = 0,
+        min_y: f64 = 0,
+        max_y: f64 = 0,
+    };
+    pub const Resolution = struct { node_entity: u64, node_id: u32, distance: f32, reuse: ReuseRegion = .{} };
 
     node_entity: u64 = 0,
     node_id: u32 = 0,
     distance: f32 = 0.0,
+    reuse: ReuseRegion = .{},
     status: Status = .pending,
     stamp: Stamp = .{},
     invalidation: Invalidation = .none,
@@ -99,6 +110,7 @@ pub const ClosestMovementNode = struct {
             self.node_entity = r.node_entity;
             self.node_id = r.node_id;
             self.distance = r.distance;
+            self.reuse = r.reuse;
             self.last_ready_stamp = snapshot;
         }
         self.stamp = snapshot;
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index 46b2ced..faa9857 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -190,6 +190,7 @@ pub const PreparationStats = struct {
     pending: usize = 0,
     selected: usize = 0,
     nearest_searches: usize = 0,
+    reused_endpoints: usize = 0,
     published: usize = 0,
     off_graph: usize = 0,
     discarded: usize = 0,
@@ -232,6 +233,7 @@ pub const State = struct {
     preparation_batch: @import("preparation_batch.zig").PreparationBatch = .{},
     preparation_snapshots: std.ArrayListUnmanaged(EndpointSnapshot) = .empty,
     graph_inputs: std.AutoHashMapUnmanaged(u32, GraphInput) = .empty,
+    registered_entities: std.ArrayListUnmanaged(?u64) = .empty,
     allocator: std.mem.Allocator,
     /// Node-ID → entity lookup. Iteration order is deterministic
     /// (insertion order) so simulation replay is stable.
@@ -318,6 +320,7 @@ pub const State = struct {
         self.preparation_batch.deinit(self.allocator);
         self.preparation_snapshots.deinit(self.allocator);
         self.graph_inputs.deinit(self.allocator);
+        self.registered_entities.deinit(self.allocator);
         self.nearest_node_cache.deinit();
         self.node_entities.deinit(self.allocator);
         self.pending_entities.deinit(self.allocator);
@@ -328,6 +331,7 @@ pub const State = struct {
 
     fn reset(self: *State, allocator: std.mem.Allocator) void {
         self.graph_inputs.clearRetainingCapacity();
+        self.registered_entities.clearRetainingCapacity();
         self.pf.deinit();
         self.node_entities.deinit(self.allocator);
         self.nearest_node_cache.deinit();
@@ -817,7 +821,7 @@ pub const Controller = struct {
         if (!ecs.entityExists(entity)) return false;
         if (ecs.hasComponent(entity, MovementNode)) return preparedEndpointNode(game, st, entity) != null;
         const cmn = ecs.getComponent(entity, ClosestMovementNode) orelse return false;
-        return cmn.current(endpointStamp(game, st, entity) orelse return false);
+        return preparedStampCurrent(game, st, entity, cmn);
     }
 
     fn preparedGraphCurrent(game: anytype, st: *State) bool {
@@ -834,15 +838,29 @@ pub const Controller = struct {
         return node.node_id;
     }
 
+    fn preparedStampCurrent(game: anytype, st: *State, entity: anytype, cmn: *const ClosestMovementNode) bool {
+        const stamp = cmn.stamp;
+        return cmn.status != .pending and stamp.world_revision == st.preparation_world and
+            stamp.entity_id == @as(u64, @intCast(entity)) and stamp.graph_revision == st.graph_epoch and
+            stamp.position_revision != 0 and game.positionRevisionAt(entity, stamp.position_slot) == stamp.position_revision;
+    }
+
+    fn registeredIdentity(st: *State, node: NodeId, entity: u64) bool {
+        return node < st.registered_entities.items.len and st.registered_entities.items[node] == entity and !st.pf.graph.isRemoved(node);
+    }
+
     fn preparedEndpointNode(game: anytype, st: *State, entity: anytype) ?NodeId {
         const ecs = &game.active_world.ecs_backend;
         if (!ecs.entityExists(entity)) return null;
-        if (ecs.hasComponent(entity, MovementNode)) return registeredNode(game, st, entity);
+        if (ecs.getComponent(entity, MovementNode)) |node| {
+            return if (registeredIdentity(st, node.node_id, @intCast(entity))) node.node_id else null;
+        }
         const cmn = ecs.getComponent(entity, ClosestMovementNode) orelse return null;
-        if (!cmn.ready(endpointStamp(game, st, entity) orelse return null)) return null;
-        const node = registeredNode(game, st, @as(@TypeOf(entity), @intCast(cmn.node_entity))) orelse return null;
-        if (node != cmn.node_id) return null;
-        return node;
+        if (cmn.status != .ready or !preparedStampCurrent(game, st, entity, cmn)) return null;
+        // The graph dependency token rejects node destruction/component changes.
+        // Its immutable, generation-qualified registration needs no ECS reread.
+        if (!registeredIdentity(st, cmn.node_id, cmn.node_entity)) return null;
+        return cmn.node_id;
     }
 
     /// Graph path-length between two game entities, via each entity's
@@ -1222,10 +1240,8 @@ pub const Controller = struct {
         while (participants.next()) |entity| {
             st.preparation_stats.discovered += 1;
             if (!ecs.entityExists(entity) or ecs.hasComponent(entity, MovementNode)) continue;
-            if (endpointStamp(game, st, entity)) |stamp| {
-                if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
-                    if (cmn.current(stamp)) continue;
-                }
+            if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
+                if (preparedStampCurrent(game, st, entity, cmn)) continue;
             }
             st.preparation_stats.pending += 1;
             st.preparation_batch.consider(@intCast(entity));
@@ -1244,14 +1260,16 @@ pub const Controller = struct {
             });
         }
         for (st.preparation_snapshots.items) |*snapshot| {
-            st.preparation_stats.nearest_searches += 1;
-            if (findNearestNodeInState(st, snapshot.position.x, snapshot.position.y)) |node| {
-                const node_entity = st.node_entities.get(node) orelse continue;
-                const pos = st.pf.graph.getPosition(node);
-                const dx = pos.x - snapshot.position.x;
-                const dy = pos.y - snapshot.position.y;
-                snapshot.resolution = .{ .node_entity = node_entity, .node_id = node, .distance = @sqrt(dx * dx + dy * dy) };
+            const entity: Entity = @intCast(snapshot.entity);
+            if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
+                if (reusePreparedResolution(st, cmn, snapshot.stamp, snapshot.position)) |resolution| {
+                    snapshot.resolution = resolution;
+                    st.preparation_stats.reused_endpoints += 1;
+                    continue;
+                }
             }
+            st.preparation_stats.nearest_searches += 1;
+            snapshot.resolution = resolvePreparedNearest(st, snapshot.position);
         }
         st.preparation_stats.selected = st.preparation_batch.selected.items.len;
         st.preparation_stats.discarded = st.preparation_stats.selected - st.preparation_snapshots.items.len;
@@ -1313,6 +1331,7 @@ pub const Controller = struct {
             // The complete ECS handle, including generation, is the identity.
             .entity_id = @intCast(entity),
             .position_revision = revision,
+            .position_slot = game.positionRevisionSlot(entity) orelse return null,
             .graph_revision = st.graph_epoch,
         };
     }
@@ -1472,6 +1491,13 @@ pub const Controller = struct {
                 log.err("failed to track node {d}: {}", .{ node_id, err });
             };
             if (st.preparation_enabled) {
+                const old_len = st.registered_entities.items.len;
+                st.registered_entities.resize(st.allocator, @as(usize, node_id) + 1) catch {
+                    watches_ok = false;
+                    continue;
+                };
+                @memset(st.registered_entities.items[old_len..], null);
+                st.registered_entities.items[node_id] = entity_id;
                 st.graph_inputs.put(st.allocator, node_id, .{
                     .position = pos,
                     .stair = is_stair,
@@ -1878,6 +1904,79 @@ pub fn cachedNearestStillValid(cached: CachedNearest, x: f32, y: f32) bool {
     return dx * dx + dy * dy < CACHE_POS_THRESHOLD_SQ;
 }
 
+/// Reuse is preparation work, never a distance-query fallback. The original
+/// sample/radius are retained so small moves cannot accumulate unchecked drift.
+fn reusePreparedResolution(st: *State, cmn: *const ClosestMovementNode, stamp: ClosestMovementNode.Stamp, pos: Position) ?ClosestMovementNode.Resolution {
+    if (cmn.status == .off_graph or !cmn.stamp.eql(cmn.last_ready_stamp) or cmn.stamp.world_revision != stamp.world_revision or
+        cmn.stamp.entity_id != stamp.entity_id or cmn.stamp.graph_revision != stamp.graph_revision or
+        cmn.invalidation == .graph or cmn.invalidation == .world) return null;
+    if (!Controller.registeredIdentity(st, cmn.node_id, cmn.node_entity)) return null;
+    const region = cmn.reuse;
+    if (!(region.radius > 0) or !std.math.isFinite(pos.x) or !std.math.isFinite(pos.y)) return null;
+    if (@as(f64, pos.y) < region.min_y or @as(f64, pos.y) >= region.max_y) return null;
+    const dx = @as(f64, pos.x) - region.x;
+    const dy = @as(f64, pos.y) - region.y;
+    if (dx * dx + dy * dy >= region.radius * region.radius) return null;
+    const node_pos = st.pf.graph.getPosition(cmn.node_id);
+    const nx = node_pos.x - pos.x;
+    const ny = node_pos.y - pos.y;
+    const distance = @sqrt(nx * nx + ny * ny);
+    if (!std.math.isFinite(distance) or distance > MAX_NODE_SNAP_DISTANCE or node_pos.y > pos.y + Y_FILTER_EPS) return null;
+    return .{ .node_entity = cmn.node_entity, .node_id = cmn.node_id, .distance = distance, .reuse = region };
+}
+
+/// Same selection/tie order as findNearestNodeInState, with a conservative region
+/// where the winner cannot change. Distance differences are 2-Lipschitz: moving
+/// less than one quarter of the runner-up gap stays strictly inside that region.
+/// Separate Y bounds preserve the eligible node set during horizontal movement.
+fn resolvePreparedNearest(st: *State, pos: Position) ?ClosestMovementNode.Resolution {
+    if (!std.math.isFinite(pos.x) or !std.math.isFinite(pos.y)) return null;
+    var best: ?NodeId = null;
+    var best_distance: f32 = std.math.inf(f32);
+    var best_exact: f64 = std.math.inf(f64);
+    var second_exact: f64 = std.math.inf(f64);
+    var min_y: f64 = -std.math.inf(f64);
+    var max_y: f64 = std.math.inf(f64);
+    for (0..st.pf.graph.totalSlots()) |i| {
+        const node: NodeId = @intCast(i);
+        if (st.pf.graph.isRemoved(node)) continue;
+        const point = st.pf.graph.getPosition(node);
+        const boundary = @as(f64, point.y) - Y_FILTER_EPS;
+        const padding = 0.00001 * @max(1, @max(@abs(@as(f64, point.y)), @abs(@as(f64, pos.y))));
+        if (point.y > pos.y + Y_FILTER_EPS) {
+            max_y = @min(max_y, boundary - padding);
+            continue;
+        }
+        min_y = @max(min_y, boundary + padding);
+        const dx = point.x - pos.x;
+        const dy = point.y - pos.y;
+        const distance = @sqrt(dx * dx + dy * dy);
+        const ex = @as(f64, point.x) - pos.x;
+        const ey = @as(f64, point.y) - pos.y;
+        const exact = @sqrt(ex * ex + ey * ey);
+        if (distance < best_distance) {
+            second_exact = @min(second_exact, best_exact);
+            best_distance = distance;
+            best_exact = exact;
+            best = node;
+        } else {
+            second_exact = @min(second_exact, exact);
+        }
+    }
+    const node = best orelse return null;
+    if (best_distance > MAX_NODE_SNAP_DISTANCE) return null;
+    const entity = st.node_entities.get(node) orelse return null;
+    const gap = if (std.math.isFinite(second_exact)) second_exact - best_exact else MAX_NODE_SNAP_DISTANCE;
+    // Leave generous room for the f32 arithmetic used by the reference selector.
+    const rounding_guard = 0.0001 * @max(1, best_exact);
+    return .{
+        .node_entity = entity,
+        .node_id = node,
+        .distance = best_distance,
+        .reuse = .{ .x = pos.x, .y = pos.y, .radius = @max(0, gap * 0.25 - rounding_guard), .min_y = min_y, .max_y = max_y },
+    };
+}
+
 pub fn findNearestNodeInState(st: *State, x: f32, y: f32) ?NodeId {
     const slots = st.pf.graph.totalSlots();
     if (slots == 0) return null;
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index 823ed82..75cced3 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -362,3 +362,88 @@ test "known docking placement validates world geometry and is invalidated by anc
     game.setPosition(parent, .{ .x = 1000 });
     try testing.expect(!try C.publishKnownEndpoint(&game, bandit, dock));
 }
+
+test "small moves reuse only during preparation and preserve the original region" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    _ = node(&game, 50);
+    const e = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try run(&game, 1);
+    const region = game.getComponent(e, CMN).?.reuse;
+    for (2..10) |x| {
+        game.setPosition(e, .{ .x = @floatFromInt(x) });
+        try testing.expectEqual(null, C.preparedDistance(&game, e, n));
+        const stats = try stage(&game, 1);
+        try testing.expectEqual(@as(usize, 1), stats.reused_endpoints);
+        try testing.expectEqual(@as(usize, 0), stats.nearest_searches);
+        try testing.expectEqual(null, C.preparedDistance(&game, e, n));
+        _ = C.publishEndpointBatch(&game);
+        try testing.expectEqual(@as(?f32, 0), C.preparedDistance(&game, e, n));
+        try testing.expectEqualDeep(region, game.getComponent(e, CMN).?.reuse);
+    }
+    game.setPosition(e, .{ .x = 30 });
+    try testing.expectEqual(@as(usize, 1), (try stage(&game, 1)).nearest_searches);
+    _ = C.publishEndpointBatch(&game);
+    try testing.expectEqual(@as(?f32, 50), C.preparedDistance(&game, e, n));
+}
+
+test "reuse agrees with exhaustive nearest selection across ties Y boundaries and teleports" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    _ = node(&game, 50);
+    const upper = node(&game, 25);
+    game.setPosition(upper, .{ .x = 25, .y = 10 });
+    _ = node(&game, 50); // duplicate: retain first-node tie order
+    const e = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    var reused: usize = 0;
+    for (0..600) |i| {
+        const x: f32 = @as(f32, @floatFromInt(i % 151)) - 40;
+        const y: f32 = switch ((i / 151) % 4) {
+            0 => 0,
+            1 => 4.99999,
+            2 => 5,
+            else => 5.00001,
+        };
+        game.setPosition(e, .{ .x = x, .y = y });
+        const stats = try run(&game, 1);
+        reused += stats.reused_endpoints;
+        const expected = pf.controller.findNearestNodeInState(C.getState(&game).?, x, y);
+        const cmn = game.getComponent(e, CMN).?;
+        if (expected) |id| {
+            try testing.expectEqual(CMN.Status.ready, cmn.status);
+            try testing.expectEqual(id, cmn.node_id);
+        } else try testing.expectEqual(CMN.Status.off_graph, cmn.status);
+    }
+    try testing.expect(reused > 0);
+    game.setPosition(e, .{ .x = 10000 });
+    try testing.expectEqual(@as(usize, 1), (try run(&game, 1)).off_graph);
+    game.setPosition(e, .{ .x = 1 });
+    try testing.expectEqual(@as(usize, 1), (try run(&game, 1)).nearest_searches);
+}
+
+test "known placements and changed graphs cannot reuse a nearest certificate" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const e = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try run(&game, 1);
+    try testing.expect(try C.publishKnownEndpoint(&game, e, n));
+    game.setPosition(e, .{ .x = 2 });
+    try testing.expectEqual(@as(usize, 1), (try run(&game, 1)).nearest_searches);
+    game.setPosition(n, .{ .x = 3 });
+    C.advance(&game, 0);
+    try testing.expectEqual(@as(usize, 1), (try run(&game, 1)).nearest_searches);
+    game.setPosition(e, .{ .x = 4 });
+    try testing.expectEqual(@as(usize, 1), (try stage(&game, 1)).reused_endpoints);
+    game.setPosition(e, .{ .x = 5 });
+    try testing.expectEqual(@as(usize, 1), C.publishEndpointBatch(&game).discarded);
+    try testing.expectEqual(null, C.preparedDistance(&game, e, n));
+}
diff --git a/tests/nav/prepared_endpoint_test.zig b/tests/nav/prepared_endpoint_test.zig
index c2e8a75..1795e55 100644
--- a/tests/nav/prepared_endpoint_test.zig
+++ b/tests/nav/prepared_endpoint_test.zig
@@ -3,7 +3,7 @@ const testing = std.testing;
 const pathfinder = @import("pathfinder");
 const CMN = pathfinder.ClosestMovementNode;
 
-const initial = CMN.Stamp{ .world_revision = 1, .entity_id = 42, .entity_generation = 0, .position_revision = 1, .graph_revision = 1 };
+const initial = CMN.Stamp{ .world_revision = 1, .entity_id = 42, .entity_generation = 0, .position_revision = 1, .position_slot = 0, .graph_revision = 1 };
 const node_zero = CMN.Resolution{ .node_entity = 7, .node_id = 0, .distance = 0 };
 
 test "CMN defaults and legacy writes stay pending; node zero can be published" {

From 9507fcdb6c9a1de7c537a31deab18e5910931d91 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 17:25:48 +0000
Subject: [PATCH 5/9] perf(pathfinder): prepare pending domains without
 per-frame discovery

---
 .github/workflows/ci.yml               |   2 +-
 src/nav/controller.zig                 |  74 ++++++++++++-
 tests/integration/preparation_test.zig | 143 +++++++++++++++++++++++++
 3 files changed, 217 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9f39bf1..ca1b784 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,7 +36,7 @@ jobs:
         run: |
           git init ../labelle-engine
           git -C ../labelle-engine remote add origin https://github.com/labelle-toolkit/labelle-engine.git
-          git -C ../labelle-engine fetch --depth 1 origin c9dddffba8f78d9e1dbd5a81d34f5623b669a2e5
+          git -C ../labelle-engine fetch --depth 1 origin 241556dc0263c975bbd4de1257ed6a6c8e3e22e5
           git -C ../labelle-engine checkout --detach FETCH_HEAD
 
       - name: Run engine integration tests
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index faa9857..d1ea5ee 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -187,6 +187,7 @@ pub const ControllerState = struct {
 
 pub const PreparationStats = struct {
     discovered: usize = 0,
+    domain_discovered: usize = 0,
     pending: usize = 0,
     selected: usize = 0,
     nearest_searches: usize = 0,
@@ -227,6 +228,9 @@ pub const State = struct {
     pf: Pf,
     preparation_world: u64,
     preparation_enabled: bool = false,
+    domain_revision: ?u64 = null,
+    domain_graph_epoch: u64 = 0,
+    domain_watches_ready: bool = false,
     graph_dependency_revision: ?u64 = null,
     preparation_in_flight: bool = false,
     preparation_stats: PreparationStats = .{},
@@ -808,6 +812,7 @@ pub const Controller = struct {
         var cmn = if (ecs.getComponent(entity, ClosestMovementNode)) |old| old.* else ClosestMovementNode{};
         if (!cmn.publish(stamp, stamp, .{ .node_entity = @intCast(node_entity), .node_id = node, .distance = distance_to_node })) return false;
         ecs.addComponent(entity, cmn);
+        game.active_world.position_revisions.acknowledge(@intCast(entity), stamp.position_revision);
         return true;
     }
 
@@ -1023,6 +1028,7 @@ pub const Controller = struct {
             const dx = node_pos.x - pos.x;
             const dy = node_pos.y - pos.y;
             const ne = st.node_entities.get(nid) orelse 0;
+            if (st.preparation_enabled) game.active_world.position_revisions.markPending(entity_id);
             ecs.addComponent(target_entity, components.ClosestMovementNode{
                 .node_entity = ne,
                 .node_id = nid,
@@ -1132,6 +1138,7 @@ pub const Controller = struct {
         const ecs = &game.active_world.ecs_backend;
         if (st.preparation_enabled) {
             if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| cmn.invalidate(.position);
+            game.active_world.position_revisions.markPending(entity_id);
             return;
         }
         const pos = game.getWorldPosition(entity);
@@ -1222,6 +1229,66 @@ pub const Controller = struct {
         st.preparation_enabled = true;
     }
 
+    /// Pending-only preparation for one fixed union of component types per
+    /// world/controller. Shared membership changes trigger discovery; ordinary
+    /// movement only enqueues already registered endpoints. Queries stay pure.
+    pub fn prepareEndpointDomains(game: anytype, comptime domains: anytype, budget: usize) !PreparationStats {
+        const st = findState(game) orelse return .{};
+        if (st.preparation_in_flight) return error.PreparationInProgress;
+        const tracker = &game.active_world.position_revisions;
+        const ecs = &game.active_world.ecs_backend;
+        if (!st.domain_watches_ready) {
+            inline for (domains) |T| try tracker.watchMembership(game.allocator, T);
+            try tracker.watchMembership(game.allocator, MovementNode);
+            try tracker.watchMembership(game.allocator, ClosestMovementNode);
+            st.domain_watches_ready = true;
+        }
+        var discovered: usize = 0;
+        if (st.domain_revision == null or st.domain_revision.? != tracker.membership_revision) {
+            // Commit the revision only after every registration succeeds. OOM
+            // leaves the discovery pass retryable and publishes nothing.
+            inline for (domains) |T| {
+                var view = ecs.view(.{T}, .{});
+                defer view.deinit();
+                while (view.next()) |entity| {
+                    discovered += 1;
+                    if (!ecs.hasComponent(entity, MovementNode)) {
+                        try tracker.watchChanges(game.allocator, @intCast(entity));
+                        const current = if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| preparedStampCurrent(game, st, entity, cmn) else false;
+                        if (!current) tracker.markPending(@intCast(entity));
+                    }
+                }
+            }
+            st.domain_revision = tracker.membership_revision;
+        }
+        if (st.domain_graph_epoch != st.graph_epoch) {
+            tracker.markAllPending();
+            st.domain_graph_epoch = st.graph_epoch;
+        }
+        const Entity = @TypeOf(game.*).EntityType;
+        var participants = struct {
+            game: @TypeOf(game),
+            pending: @TypeOf(tracker.pendingIterator()),
+            pub fn next(self: *@This()) ?Entity {
+                while (self.pending.next()) |id| {
+                    const entity: Entity = @intCast(id);
+                    const backend = &self.game.active_world.ecs_backend;
+                    if (backend.entityExists(entity) and !backend.hasComponent(entity, MovementNode)) {
+                        inline for (domains) |T| {
+                            if (backend.hasComponent(entity, T)) return entity;
+                        }
+                    }
+                    self.game.active_world.position_revisions.unwatchChanges(id);
+                }
+                return null;
+            }
+        }{ .game = game, .pending = tracker.pendingIterator() };
+        var result = try prepareEndpointBatch(game, &participants, budget);
+        result.domain_discovered = discovered;
+        st.preparation_stats.domain_discovered = discovered;
+        return result;
+    }
+
     /// Serial snapshot + compute phase. Feed a union of game-owned domain views
     /// once per frame after movement. The caller owns/deinitializes the iterator
     /// before calling publishEndpointBatch. No CMN is written here.
@@ -1241,7 +1308,10 @@ pub const Controller = struct {
             st.preparation_stats.discovered += 1;
             if (!ecs.entityExists(entity) or ecs.hasComponent(entity, MovementNode)) continue;
             if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
-                if (preparedStampCurrent(game, st, entity, cmn)) continue;
+                if (preparedStampCurrent(game, st, entity, cmn)) {
+                    game.active_world.position_revisions.acknowledge(@intCast(entity), cmn.stamp.position_revision);
+                    continue;
+                }
             }
             st.preparation_stats.pending += 1;
             st.preparation_batch.consider(@intCast(entity));
@@ -1311,6 +1381,7 @@ pub const Controller = struct {
                         var cmn = if (ecs.getComponent(entity, ClosestMovementNode)) |old| old.* else ClosestMovementNode{};
                         if (cmn.publish(snapshot.stamp, stamp, snapshot.resolution)) {
                             ecs.addComponent(entity, cmn);
+                            game.active_world.position_revisions.acknowledge(snapshot.entity, stamp.position_revision);
                             st.preparation_stats.published += 1;
                             if (snapshot.resolution == null) st.preparation_stats.off_graph += 1;
                             continue;
@@ -2038,6 +2109,7 @@ fn settleArrival(game: anytype, st: *State, entity_id: u64, goal_node: ?NodeId)
     if (!ecs.entityExists(entity)) return;
 
     ecs.removeComponent(entity, Navigating);
+    if (st.preparation_enabled) game.active_world.position_revisions.markPending(entity_id);
 
     // CMN refresh replaces the old game-side arrival → NeedsClosestNode
     // marker → next-tick resolve round-trip: the plugin owns the CMN
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index 75cced3..c1f7199 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -447,3 +447,146 @@ test "known placements and changed graphs cannot reuse a nearest certificate" {
     try testing.expectEqual(@as(usize, 1), C.publishEndpointBatch(&game).discarded);
     try testing.expectEqual(null, C.preparedDistance(&game, e, n));
 }
+
+fn domainRun(game: *Game, budget: usize) !pf.controller.PreparationStats {
+    _ = try C.prepareEndpointDomains(game, .{Participant}, budget);
+    return C.publishEndpointBatch(game);
+}
+
+test "pending-only domains drain and idle frames visit no participants" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const parent = game.createEntity();
+    const a = item(&game, 1);
+    const b = item(&game, 2);
+    game.setParent(a, parent, .{});
+    try setup(&game);
+    defer C.deinit(&game);
+    const first = try domainRun(&game, 1);
+    try testing.expectEqual(@as(usize, 2), first.domain_discovered);
+    try testing.expectEqual(@as(usize, 2), first.discovered);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).discovered);
+    for (0..5) |_| {
+        const idle = try domainRun(&game, 1);
+        try testing.expectEqual(@as(usize, 0), idle.domain_discovered);
+        try testing.expectEqual(@as(usize, 0), idle.discovered);
+        try testing.expectEqual(@as(usize, 0), idle.nearest_searches);
+    }
+    game.setPosition(parent, .{ .x = 3 });
+    try testing.expectEqual(null, C.preparedDistance(&game, a, n));
+    const moved = try C.prepareEndpointDomains(&game, .{Participant}, 1);
+    try testing.expectEqual(@as(usize, 0), moved.domain_discovered);
+    try testing.expectEqual(@as(usize, 1), moved.discovered);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, n));
+    _ = C.publishEndpointBatch(&game);
+    try testing.expectEqual(@as(?f32, 0), C.preparedDistance(&game, a, b));
+    game.setComponent(a, Participant{ .value = 3 });
+    try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 1)).domain_discovered);
+}
+
+test "pending domains discover additions and component removal without count heuristics" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    const a = item(&game, 1);
+    const b = game.createEntity();
+    game.setPosition(b, .{ .x = 2 });
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 4);
+    game.removeComponent(a, Participant);
+    game.addComponent(b, Participant{}); // same participant count, different identity
+    game.setPosition(a, .{ .x = 4 });
+    const changed = try domainRun(&game, 4);
+    try testing.expectEqual(@as(usize, 1), changed.domain_discovered);
+    try testing.expectEqual(@as(usize, 1), changed.published);
+    try testing.expect(C.endpointPreparationComplete(&game, b));
+    game.setPosition(a, .{ .x = 5 });
+    try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 4)).discovered);
+    game.active_world.ecs_backend.addComponent(a, Participant{});
+    game.invalidateComponentMembership(Participant);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 4)).published);
+    game.destroyEntity(b);
+    try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 4)).discovered);
+}
+
+test "pending work survives cancellation stale publication off graph and repath" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    const a = item(&game, 1);
+    const b = item(&game, 10000);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try C.prepareEndpointDomains(&game, .{Participant}, 1);
+    C.cancelEndpointBatch(&game);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+    _ = try C.prepareEndpointDomains(&game, .{Participant}, 1);
+    game.setPosition(b, .{ .x = 20000 });
+    try testing.expectEqual(@as(usize, 1), C.publishEndpointBatch(&game).discarded);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).off_graph);
+    try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 1)).discovered);
+    C.requestRepath(&game, a);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+    game.setPosition(b, .{ .x = 2 });
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+}
+
+test "graph changes and node role changes requeue endpoints; moving entities cannot starve others" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const a = item(&game, 1);
+    const b = item(&game, 2);
+    const c = item(&game, 3);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 1);
+    game.setPosition(a, .{ .x = 4 });
+    _ = try domainRun(&game, 1);
+    try testing.expect(C.endpointPreparationComplete(&game, b));
+    game.setPosition(a, .{ .x = 5 });
+    _ = try domainRun(&game, 1);
+    try testing.expect(C.endpointPreparationComplete(&game, c));
+    _ = try domainRun(&game, 4);
+    game.setPosition(n, .{ .x = 10 });
+    C.advance(&game, 0);
+    const rebuilt = try domainRun(&game, 4);
+    try testing.expectEqual(@as(usize, 0), rebuilt.domain_discovered);
+    try testing.expectEqual(@as(usize, 3), rebuilt.published);
+    game.addComponent(a, pf.MovementNode{});
+    C.advance(&game, 0);
+    _ = try domainRun(&game, 4);
+    game.removeComponent(a, pf.MovementNode);
+    C.advance(&game, 0);
+    _ = try domainRun(&game, 4);
+    try testing.expect(C.endpointPreparationComplete(&game, a));
+}
+
+test "pending discovery retries after allocation failure and controller replacement" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    const e = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    const state = C.getState(&game).?;
+    var bytes: [0]u8 = .{};
+    var allocator = std.heap.FixedBufferAllocator.init(&bytes);
+    {
+        state.allocator = allocator.allocator();
+        defer state.allocator = testing.allocator;
+        try testing.expectError(error.OutOfMemory, C.prepareEndpointDomains(&game, .{Participant}, 1));
+    }
+    try testing.expect(!C.endpointPreparationComplete(&game, e));
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+    const old_world = game.getComponent(e, CMN).?.stamp.world_revision;
+    try C.setup(&game);
+    C.enableEndpointPreparation(&game);
+    C.advance(&game, 0);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+    try testing.expect(game.getComponent(e, CMN).?.stamp.world_revision != old_world);
+    game.removeComponent(e, CMN);
+    try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
+}

From fb32341efa3d6e09715a0097c4aa27a846b80a49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 17:29:18 +0000
Subject: [PATCH 6/9] test(pathfinder): compare pending preparation with
 full-view reference

---
 tests/integration/preparation_test.zig | 55 ++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index c1f7199..352f593 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -590,3 +590,58 @@ test "pending discovery retries after allocation failure and controller replacem
     game.removeComponent(e, CMN);
     try testing.expectEqual(@as(usize, 1), (try domainRun(&game, 1)).published);
 }
+
+test "pending and full-view preparation publish identical frame outcomes" {
+    var reference = Game.init(testing.allocator);
+    defer reference.deinit();
+    var queued = Game.init(testing.allocator);
+    defer queued.deinit();
+    const rn = node(&reference, 0);
+    const qn = node(&queued, 0);
+    _ = node(&reference, 50);
+    _ = node(&queued, 50);
+    var re: [6]Entity = undefined;
+    var qe: [6]Entity = undefined;
+    for (0..5) |i| {
+        re[i] = item(&reference, @floatFromInt(i * 10));
+        qe[i] = item(&queued, @floatFromInt(i * 10));
+    }
+    try setup(&reference);
+    defer C.deinit(&reference);
+    try setup(&queued);
+    defer C.deinit(&queued);
+    var count: usize = 5;
+    for (0..60) |frame| {
+        if (frame == 10) {
+            re[5] = item(&reference, 10000);
+            qe[5] = item(&queued, 10000);
+            count = 6;
+        }
+        if (frame == 20) {
+            reference.removeComponent(re[2], Participant);
+            queued.removeComponent(qe[2], Participant);
+        }
+        if (frame == 30) {
+            reference.addComponent(re[2], Participant{});
+            queued.addComponent(qe[2], Participant{});
+        }
+        if (frame == 40) {
+            reference.setPosition(rn, .{ .x = 5 });
+            queued.setPosition(qn, .{ .x = 5 });
+            C.advance(&reference, 0);
+            C.advance(&queued, 0);
+        }
+        const i = frame % count;
+        const pos = engine.Position{ .x = @floatFromInt(frame % 70) };
+        reference.setPosition(re[i], pos);
+        queued.setPosition(qe[i], pos);
+        const full = try run(&reference, 2);
+        const pending = try domainRun(&queued, 2);
+        try testing.expectEqual(full.selected, pending.selected);
+        try testing.expectEqual(full.published, pending.published);
+        try testing.expectEqual(full.off_graph, pending.off_graph);
+        for (0..count) |j| {
+            try testing.expectEqual(C.preparedDistance(&reference, re[j], rn), C.preparedDistance(&queued, qe[j], qn));
+        }
+    }
+}

From 944d754326a1dfa497696d517f95747be4ab3b76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 17:53:53 +0000
Subject: [PATCH 7/9] feat: finish prepared queries and deterministic snapshot
 worker execution

---
 .github/workflows/ci.yml               |   6 +-
 src/nav/controller.zig                 | 112 +++++++++++++++++++++----
 tests/integration/preparation_test.zig |  88 +++++++++++++++++++
 3 files changed, 187 insertions(+), 19 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ca1b784..3d5106f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,8 +36,12 @@ jobs:
         run: |
           git init ../labelle-engine
           git -C ../labelle-engine remote add origin https://github.com/labelle-toolkit/labelle-engine.git
-          git -C ../labelle-engine fetch --depth 1 origin 241556dc0263c975bbd4de1257ed6a6c8e3e22e5
+          git -C ../labelle-engine fetch --depth 1 origin 2c4b0c17a669e520ff01f409714195d3b913ba57
           git -C ../labelle-engine checkout --detach FETCH_HEAD
 
       - name: Run engine integration tests
         run: zig build test --build-file tests/integration/build.zig --summary all
+
+      - name: Compile serial and threaded WASM snapshot executor
+        working-directory: ../labelle-engine
+        run: zig build snapshot-worker-check
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index d1ea5ee..166ca1a 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -192,6 +192,7 @@ pub const PreparationStats = struct {
     selected: usize = 0,
     nearest_searches: usize = 0,
     reused_endpoints: usize = 0,
+    worker_executed: bool = false,
     published: usize = 0,
     off_graph: usize = 0,
     discarded: usize = 0,
@@ -203,7 +204,9 @@ const GraphInput = struct {
     stair: bool,
     link: ?MovementLink,
 };
+const SearchNode = struct { id: NodeId, entity: u64, position: Position };
 const EndpointSnapshot = struct {
+    search: bool = true,
     entity: u64,
     stamp: ClosestMovementNode.Stamp,
     position: Position,
@@ -228,6 +231,9 @@ pub const State = struct {
     pf: Pf,
     preparation_world: u64,
     preparation_enabled: bool = false,
+    preparation_worker: bool = false,
+    search_nodes: std.ArrayListUnmanaged(SearchNode) = .empty,
+    search_epoch: u64 = 0,
     domain_revision: ?u64 = null,
     domain_graph_epoch: u64 = 0,
     domain_watches_ready: bool = false,
@@ -323,6 +329,7 @@ pub const State = struct {
     pub fn deinit(self: *State) void {
         self.preparation_batch.deinit(self.allocator);
         self.preparation_snapshots.deinit(self.allocator);
+        self.search_nodes.deinit(self.allocator);
         self.graph_inputs.deinit(self.allocator);
         self.registered_entities.deinit(self.allocator);
         self.nearest_node_cache.deinit();
@@ -792,6 +799,45 @@ pub const Controller = struct {
         return st.pf.preparedNodeDistance(from, to);
     }
 
+    /// Reuse a validated origin across a destination scan; every lookup still
+    /// rejects changes to the origin, world, graph, or destination.
+    pub fn preparedDistancesFrom(game: anytype, entity: anytype) ?PreparedDistances(@TypeOf(game), @TypeOf(entity)) {
+        const st = findState(game) orelse return null;
+        if (!preparedGraphCurrent(game, st)) return null;
+        const node = preparedEndpointNode(game, st, entity) orelse return null;
+        const stamp = if (game.active_world.ecs_backend.hasComponent(entity, MovementNode)) null else game.active_world.ecs_backend.getComponent(entity, ClosestMovementNode).?.stamp;
+        return .{ .game = game, .entity = entity, .node = node, .world = st.preparation_world, .epoch = st.graph_epoch, .stamp = stamp };
+    }
+
+    pub fn PreparedDistances(comptime GamePtr: type, comptime Entity: type) type {
+        return struct {
+            game: GamePtr,
+            entity: Entity,
+            node: NodeId,
+            world: u64,
+            epoch: u64,
+            stamp: ?ClosestMovementNode.Stamp,
+            pub fn to(self: *const @This(), target: anytype) ?f32 {
+                const st = findState(self.game) orelse return null;
+                if (st.preparation_world != self.world or st.graph_epoch != self.epoch or !preparedGraphCurrent(self.game, st)) return null;
+                if (self.stamp) |stamp| {
+                    const cmn = self.game.active_world.ecs_backend.getComponent(self.entity, ClosestMovementNode) orelse return null;
+                    if (cmn.node_id != self.node or !cmn.ready(stamp) or self.game.positionRevisionAt(self.entity, stamp.position_slot) != stamp.position_revision) return null;
+                    if (!registeredIdentity(st, self.node, cmn.node_entity)) return null;
+                } else if (!registeredIdentity(st, self.node, @intCast(self.entity))) return null;
+                const target_node = preparedEndpointNode(self.game, st, target) orelse return null;
+                return st.pf.preparedNodeDistance(self.node, target_node);
+            }
+        };
+    }
+
+    /// Optional shared worker execution. Serial remains the default. A supported
+    /// host may run one half on its persistent worker and one on the main thread;
+    /// every result is joined before prepare returns and remains unpublished.
+    pub fn setPreparationWorker(game: anytype, enabled: bool) void {
+        if (findState(game)) |st| st.preparation_worker = enabled;
+    }
+
     /// Publish a known placement (for example a ship's docking node). This
     /// command validates the actual world-space position; it never scans for
     /// another node and never attaches a CMN to a MovementNode.
@@ -1028,8 +1074,7 @@ pub const Controller = struct {
             const dx = node_pos.x - pos.x;
             const dy = node_pos.y - pos.y;
             const ne = st.node_entities.get(nid) orelse 0;
-            if (st.preparation_enabled) game.active_world.position_revisions.markPending(entity_id);
-            ecs.addComponent(target_entity, components.ClosestMovementNode{
+            if (!st.preparation_enabled) ecs.addComponent(target_entity, components.ClosestMovementNode{
                 .node_entity = ne,
                 .node_id = nid,
                 .distance = @sqrt(dx * dx + dy * dy),
@@ -1127,11 +1172,9 @@ pub const Controller = struct {
         return @sqrt(dx * dx + dy * dy);
     }
 
-    /// Re-resolve the entity's `ClosestMovementNode` immediately (v4:
-    /// replaces the game-side `PendingRepath` marker + next-tick
-    /// resolve round-trip — the plugin owns the CMN component, so
-    /// there's nothing to defer). Removes the CMN when the entity is
-    /// off-graph (no node within `MAX_NODE_SNAP_DISTANCE`).
+    /// In preparation mode, invalidate and queue the endpoint while retaining
+    /// its last published node for debugging. Legacy mode resolves immediately
+    /// and removes the component if no node is in range.
     pub fn requestRepath(game: anytype, entity: anytype) void {
         const st = findState(game) orelse return;
         const entity_id: u64 = @intCast(entity);
@@ -1316,6 +1359,16 @@ pub const Controller = struct {
             st.preparation_stats.pending += 1;
             st.preparation_batch.consider(@intCast(entity));
         }
+        if (st.search_epoch != st.graph_epoch) {
+            st.search_nodes.clearRetainingCapacity();
+            try st.search_nodes.ensureTotalCapacity(st.allocator, st.pf.graph.totalSlots());
+            for (0..st.pf.graph.totalSlots()) |i| {
+                const id: NodeId = @intCast(i);
+                if (st.pf.graph.isRemoved(id)) continue;
+                st.search_nodes.appendAssumeCapacity(.{ .id = id, .entity = st.node_entities.get(id) orelse continue, .position = st.pf.graph.getPosition(id) });
+            }
+            st.search_epoch = st.graph_epoch;
+        }
         const Entity = @TypeOf(game.*).EntityType;
         // Snapshot every selected entity before searching or publishing any.
         // OOM can register revision tokens, but cannot publish a partial batch.
@@ -1334,13 +1387,17 @@ pub const Controller = struct {
             if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
                 if (reusePreparedResolution(st, cmn, snapshot.stamp, snapshot.position)) |resolution| {
                     snapshot.resolution = resolution;
+                    snapshot.search = false;
                     st.preparation_stats.reused_endpoints += 1;
                     continue;
                 }
             }
             st.preparation_stats.nearest_searches += 1;
-            snapshot.resolution = resolvePreparedNearest(st, snapshot.position);
         }
+        var job = SearchJob{ .nodes = st.search_nodes.items, .endpoints = st.preparation_snapshots.items };
+        if (st.preparation_worker) {
+            st.preparation_stats.worker_executed = game.active_world.snapshot_executor.run(&job, job.endpoints.len, SearchJob.run);
+        } else SearchJob.run(&job, 0, job.endpoints.len);
         st.preparation_stats.selected = st.preparation_batch.selected.items.len;
         st.preparation_stats.discarded = st.preparation_stats.selected - st.preparation_snapshots.items.len;
         st.preparation_in_flight = true;
@@ -1996,22 +2053,31 @@ fn reusePreparedResolution(st: *State, cmn: *const ClosestMovementNode, stamp: C
     return .{ .node_entity = cmn.node_entity, .node_id = cmn.node_id, .distance = distance, .reuse = region };
 }
 
+const SearchJob = struct {
+    nodes: []const SearchNode,
+    endpoints: []EndpointSnapshot,
+    fn run(raw: *anyopaque, start: usize, end: usize) void {
+        const job: *@This() = @ptrCast(@alignCast(raw));
+        for (job.endpoints[start..end]) |*endpoint| {
+            if (endpoint.search) endpoint.resolution = resolvePreparedNearest(job.nodes, endpoint.position);
+        }
+    }
+};
+
 /// Same selection/tie order as findNearestNodeInState, with a conservative region
 /// where the winner cannot change. Distance differences are 2-Lipschitz: moving
 /// less than one quarter of the runner-up gap stays strictly inside that region.
 /// Separate Y bounds preserve the eligible node set during horizontal movement.
-fn resolvePreparedNearest(st: *State, pos: Position) ?ClosestMovementNode.Resolution {
+fn resolvePreparedNearest(nodes: []const SearchNode, pos: Position) ?ClosestMovementNode.Resolution {
     if (!std.math.isFinite(pos.x) or !std.math.isFinite(pos.y)) return null;
-    var best: ?NodeId = null;
+    var best: ?SearchNode = null;
     var best_distance: f32 = std.math.inf(f32);
     var best_exact: f64 = std.math.inf(f64);
     var second_exact: f64 = std.math.inf(f64);
     var min_y: f64 = -std.math.inf(f64);
     var max_y: f64 = std.math.inf(f64);
-    for (0..st.pf.graph.totalSlots()) |i| {
-        const node: NodeId = @intCast(i);
-        if (st.pf.graph.isRemoved(node)) continue;
-        const point = st.pf.graph.getPosition(node);
+    for (nodes) |node| {
+        const point = node.position;
         const boundary = @as(f64, point.y) - Y_FILTER_EPS;
         const padding = 0.00001 * @max(1, @max(@abs(@as(f64, point.y)), @abs(@as(f64, pos.y))));
         if (point.y > pos.y + Y_FILTER_EPS) {
@@ -2036,13 +2102,13 @@ fn resolvePreparedNearest(st: *State, pos: Position) ?ClosestMovementNode.Resolu
     }
     const node = best orelse return null;
     if (best_distance > MAX_NODE_SNAP_DISTANCE) return null;
-    const entity = st.node_entities.get(node) orelse return null;
+
     const gap = if (std.math.isFinite(second_exact)) second_exact - best_exact else MAX_NODE_SNAP_DISTANCE;
     // Leave generous room for the f32 arithmetic used by the reference selector.
     const rounding_guard = 0.0001 * @max(1, best_exact);
     return .{
-        .node_entity = entity,
-        .node_id = node,
+        .node_entity = node.entity,
+        .node_id = node.id,
         .distance = best_distance,
         .reuse = .{ .x = pos.x, .y = pos.y, .radius = @max(0, gap * 0.25 - rounding_guard), .min_y = min_y, .max_y = max_y },
     };
@@ -2109,7 +2175,17 @@ fn settleArrival(game: anytype, st: *State, entity_id: u64, goal_node: ?NodeId)
     if (!ecs.entityExists(entity)) return;
 
     ecs.removeComponent(entity, Navigating);
-    if (st.preparation_enabled) game.active_world.position_revisions.markPending(entity_id);
+    if (st.preparation_enabled) {
+        var arrival_node: u64 = 0;
+        if (goal_node) |node| {
+            if (st.node_entities.get(node)) |node_entity| {
+                if (Controller.publishKnownEndpoint(game, entity, @as(Entity, @intCast(node_entity))) catch false) arrival_node = node_entity;
+            }
+        }
+        if (arrival_node == 0) Controller.requestRepath(game, entity);
+        emitGameEvent(game, "pathfinder__arrived", .{ .entity = entity_id, .node_entity = arrival_node });
+        return;
+    }
 
     // CMN refresh replaces the old game-side arrival → NeedsClosestNode
     // marker → next-tick resolve round-trip: the plugin owns the CMN
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index 352f593..6211ea5 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -610,6 +610,7 @@ test "pending and full-view preparation publish identical frame outcomes" {
     defer C.deinit(&reference);
     try setup(&queued);
     defer C.deinit(&queued);
+    C.setPreparationWorker(&queued, true);
     var count: usize = 5;
     for (0..60) |frame| {
         if (frame == 10) {
@@ -645,3 +646,90 @@ test "pending and full-view preparation publish identical frame outcomes" {
         }
     }
 }
+
+test "prepared origin scans reject movement repath destruction and controller replacement" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const n2 = node(&game, 50);
+    const a = item(&game, 1);
+    const b = item(&game, 51);
+    try setup(&game);
+    defer C.deinit(&game);
+    try testing.expectEqual(null, C.preparedDistancesFrom(&game, a));
+    _ = try domainRun(&game, 8);
+    var scan = C.preparedDistancesFrom(&game, a).?;
+    try testing.expectEqual(C.preparedDistance(&game, a, b), scan.to(b));
+    // A validated known placement can change the node without changing the stamp.
+    try testing.expect(try C.publishKnownEndpoint(&game, a, n2));
+    try testing.expectEqual(null, scan.to(b));
+    scan = C.preparedDistancesFrom(&game, a).?;
+    C.requestRepath(&game, a);
+    try testing.expectEqual(null, scan.to(b));
+    _ = try domainRun(&game, 8);
+    scan = C.preparedDistancesFrom(&game, a).?;
+    game.setPosition(a, .{ .x = 2 });
+    try testing.expectEqual(null, scan.to(b));
+    _ = try domainRun(&game, 8);
+    scan = C.preparedDistancesFrom(&game, a).?;
+    var direct = C.preparedDistancesFrom(&game, n).?;
+    game.setPosition(n2, .{ .x = 60 });
+    try testing.expectEqual(null, scan.to(b));
+    try testing.expectEqual(null, direct.to(n));
+    C.advance(&game, 0);
+    _ = try domainRun(&game, 8);
+    scan = C.preparedDistancesFrom(&game, a).?;
+    try C.setup(&game);
+    C.enableEndpointPreparation(&game);
+    C.advance(&game, 0);
+    _ = try domainRun(&game, 8);
+    try testing.expectEqual(null, scan.to(b));
+    scan = C.preparedDistancesFrom(&game, a).?;
+    game.destroyEntity(a);
+    try testing.expectEqual(null, scan.to(b));
+}
+
+test "worker batch joins all results and retains publication cancellation and stale checks" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const a = item(&game, 1);
+    const b = item(&game, 2);
+    const c = item(&game, 10000);
+    try setup(&game);
+    defer C.deinit(&game);
+    C.setPreparationWorker(&game, true);
+    const computed = try C.prepareEndpointDomains(&game, .{Participant}, 3);
+    if (!@import("builtin").single_threaded) try testing.expect(computed.worker_executed);
+    try testing.expectEqual(null, C.preparedDistance(&game, a, n));
+    C.cancelEndpointBatch(&game);
+    try testing.expect(!game.hasComponent(a, CMN));
+    _ = try C.prepareEndpointDomains(&game, .{Participant}, 3);
+    game.setPosition(b, .{ .x = 3 });
+    const published = C.publishEndpointBatch(&game);
+    try testing.expectEqual(@as(usize, 1), published.discarded);
+    try testing.expectEqual(@as(usize, 1), published.off_graph);
+    try testing.expectEqual(@as(?f32, 0), C.preparedDistance(&game, a, n));
+    try testing.expectEqual(null, C.preparedDistance(&game, b, n));
+    try testing.expect(C.endpointPreparationComplete(&game, c));
+    _ = try domainRun(&game, 3);
+    try testing.expectEqual(@as(?f32, 0), C.preparedDistance(&game, b, n));
+}
+
+test "legacy navigation target lookup preserves stale matching debug records" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    _ = node(&game, 50);
+    const a = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 1);
+    game.setPosition(a, .{ .x = 51 });
+    const old = game.getComponent(a, CMN).?.*;
+    _ = C.targetPosition(&game, a);
+    try testing.expectEqualDeep(old, game.getComponent(a, CMN).?.*);
+    try testing.expect(!C.endpointPreparationComplete(&game, a));
+    _ = try domainRun(&game, 1);
+    try testing.expect(C.endpointPreparationComplete(&game, a));
+}

From ea91ff0b76c1753819bb03324897d4a65b501bd7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Thu, 15 Oct 2026 21:46:01 +0000
Subject: [PATCH 8/9] feat: maintain prepared endpoints from walker routes

---
 .github/workflows/ci.yml               |  2 +-
 build.zig.zon                          |  2 +-
 src/nav/controller.zig                 | 77 +++++++++++++++++++++++++-
 src/nav/engine.zig                     |  4 ++
 tests/integration/preparation_test.zig | 70 +++++++++++++++++++++++
 5 files changed, 150 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3d5106f..e7ea22f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,7 +36,7 @@ jobs:
         run: |
           git init ../labelle-engine
           git -C ../labelle-engine remote add origin https://github.com/labelle-toolkit/labelle-engine.git
-          git -C ../labelle-engine fetch --depth 1 origin 2c4b0c17a669e520ff01f409714195d3b913ba57
+          git -C ../labelle-engine fetch --depth 1 origin 21ea60c67038416c007e308814c137358104353d
           git -C ../labelle-engine checkout --detach FETCH_HEAD
 
       - name: Run engine integration tests
diff --git a/build.zig.zon b/build.zig.zon
index 0f42101..2e11fa6 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -3,7 +3,7 @@
     // v3.0.0 — repurposed: the ECS navigation Controller (promoted from
     // flying-platform) is now the headline API; the standalone algorithm core
     // moves under `.algo`; the old position-owning engine is dropped.
-    .version = "4.2.0",
+    .version = "4.3.0-rc.1",
     .fingerprint = 0x15f62ccc39d14685,
     .minimum_zig_version = "0.16.0",
     .dependencies = .{
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index 166ca1a..4912117 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -853,15 +853,72 @@ pub const Controller = struct {
         const dy = pos.y - anchor.y;
         const distance_to_node = @sqrt(dx * dx + dy * dy);
         if (!std.math.isFinite(distance_to_node) or distance_to_node > MAX_NODE_SNAP_DISTANCE or anchor.y > pos.y + Y_FILTER_EPS) return false;
+        return publishEndpointAt(game, st, entity, node, @intCast(node_entity), distance_to_node);
+    }
+
+    fn publishEndpointAt(game: anytype, st: *State, entity: anytype, node: NodeId, node_entity: u64, distance_to_node: f32) !bool {
+        const ecs = &game.active_world.ecs_backend;
         _ = try game.trackPositionRevision(entity);
         const stamp = endpointStamp(game, st, entity) orelse return false;
         var cmn = if (ecs.getComponent(entity, ClosestMovementNode)) |old| old.* else ClosestMovementNode{};
-        if (!cmn.publish(stamp, stamp, .{ .node_entity = @intCast(node_entity), .node_id = node, .distance = distance_to_node })) return false;
+        if (!cmn.publish(stamp, stamp, .{ .node_entity = node_entity, .node_id = node, .distance = distance_to_node })) return false;
         ecs.addComponent(entity, cmn);
         game.active_world.position_revisions.acknowledge(@intCast(entity), stamp.position_revision);
         return true;
     }
 
+    /// A graph walker owns its current edge. Resolve only its two endpoints,
+    /// never the whole graph. A point on a long authored edge is on-graph even
+    /// beyond the off-route snap radius. External movement fails this geometric
+    /// check and leaves the entity pending for ordinary preparation.
+    fn publishWalkingEndpoint(game: anytype, st: *State, entity: anytype, path: *const movement_path.MovementPath) void {
+        if (!st.preparation_enabled or !preparedGraphCurrent(game, st) or path.len == 0) return;
+        const idx = @min(path.current_index, path.len - 1);
+        const prev = if (idx > 0) idx - 1 else idx;
+        const a = path.positions[prev];
+        const b = path.positions[idx];
+        const pos = game.getWorldPosition(entity);
+        const dx = b.x - a.x;
+        const dy = b.y - a.y;
+        const length2 = dx * dx + dy * dy;
+        const t = if (length2 > 0) ((pos.x - a.x) * dx + (pos.y - a.y) * dy) / length2 else 0;
+        const px = a.x + std.math.clamp(t, 0, 1) * dx;
+        const py = a.y + std.math.clamp(t, 0, 1) * dy;
+        const on_edge = idx > 0 and @abs(pos.x - px) <= 0.05 and @abs(pos.y - py) <= 0.05;
+        var best: ?NodeId = null;
+        var best_distance: f32 = std.math.inf(f32);
+        for ([_]u32{ prev, idx }) |i| {
+            const nid = path.node_path[i];
+            const node_entity = st.node_entities.get(nid) orelse continue;
+            if (!registeredIdentity(st, nid, node_entity)) continue;
+            const anchor = st.pf.graph.getPosition(nid);
+            if (anchor.y > pos.y + Y_FILTER_EPS) continue;
+            const node_distance = @sqrt((pos.x - anchor.x) * (pos.x - anchor.x) + (pos.y - anchor.y) * (pos.y - anchor.y));
+            if (!on_edge and node_distance > MAX_NODE_SNAP_DISTANCE) continue;
+            if (node_distance < best_distance or (node_distance == best_distance and nid < (best orelse std.math.maxInt(NodeId)))) {
+                best = nid;
+                best_distance = node_distance;
+            }
+        }
+        if (best) |nid| {
+            if (publishEndpointAt(game, st, entity, nid, st.node_entities.get(nid).?, best_distance) catch false)
+                publishAttachedEndpoints(game, entity, @intCast(st.node_entities.get(nid).?));
+        }
+    }
+
+    // Carried items follow the walker's known node while within the normal
+    // placement radius. Only already tracked descendants participate; dropping
+    // or moving them independently still invalidates through the shared API.
+    fn publishAttachedEndpoints(game: anytype, parent: anytype, node_entity: @TypeOf(parent)) void {
+        if (comptime @hasDecl(@TypeOf(game.*), "getChildren")) {
+            for (game.getChildren(parent)) |child| {
+                if (game.positionRevision(child) != null)
+                    _ = publishKnownEndpoint(game, child, node_entity) catch false;
+                publishAttachedEndpoints(game, child, node_entity);
+            }
+        }
+    }
+
     /// Lifecycle gate, separate from matching: false means retry preparation
     /// before concluding that an active job/raid has no reachable candidates.
     /// Off-graph is a completed result, while pending/stale is not.
@@ -1332,7 +1389,7 @@ pub const Controller = struct {
         return result;
     }
 
-    /// Serial snapshot + compute phase. Feed a union of game-owned domain views
+    /// Joined snapshot + compute phase. Feed a union of game-owned domain views
     /// once per frame after movement. The caller owns/deinitializes the iterator
     /// before calling publishEndpointBatch. No CMN is written here.
     pub fn prepareEndpointBatch(game: anytype, participants: anytype, budget: usize) !PreparationStats {
@@ -1749,7 +1806,16 @@ pub const Controller = struct {
             const pos = game.getPosition(entity);
             switch (directStep(pos, dm.target, dm.speed, dt)) {
                 .arrived => settled.append(st.allocator, entity_id) catch break,
-                .move => |next| game.setPosition(entity, next),
+                .move => |next| {
+                    game.setPosition(entity, next);
+                    if (st.preparation_enabled) {
+                        if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
+                            const known: Entity = @intCast(cmn.node_entity);
+                            if (publishKnownEndpoint(game, entity, known) catch false)
+                                publishAttachedEndpoints(game, entity, known);
+                        }
+                    }
+                },
             }
         }
 
@@ -2272,6 +2338,11 @@ fn GameCtx(comptime GameType: type) type {
         game: GameType,
         st: *State,
 
+        pub fn onPathStep(self: *@This(), entity_id: u64, path: *const movement_path.MovementPath) void {
+            const Entity = @TypeOf(self.game.*).EntityType;
+            Controller.publishWalkingEndpoint(self.game, self.st, @as(Entity, @intCast(entity_id)), path);
+        }
+
         pub fn onArrived(self: *@This(), entity_id: u64, goal_node: NodeId) void {
             settleArrival(self.game, self.st, entity_id, goal_node);
         }
diff --git a/src/nav/engine.zig b/src/nav/engine.zig
index edc0311..b6e6b26 100644
--- a/src/nav/engine.zig
+++ b/src/nav/engine.zig
@@ -240,6 +240,10 @@ pub fn PathfinderWith(
                     break;
                 }
 
+                // Publish the walker's route endpoint after all movement for
+                // this entity, before arrival callbacks or gameplay matching.
+                if (comptime @hasDecl(@TypeOf(ctx.*), "onPathStep")) ctx.onPathStep(entity, path);
+
                 // Check if arrived at final destination
                 if (path.current_index >= path.len) {
                     arrived_list.append(self.allocator, entity) catch |err| {
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index 6211ea5..6b51858 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -733,3 +733,73 @@ test "legacy navigation target lookup preserves stale matching debug records" {
     _ = try domainRun(&game, 1);
     try testing.expect(C.endpointPreparationComplete(&game, a));
 }
+
+test "walkers publish each frame without spending the preparation search budget" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    _ = node(&game, 70);
+    const goal = node(&game, 140);
+    const mover = item(&game, 0);
+    const carried = item(&game, 0);
+    game.setParent(carried, mover, .{});
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 8);
+    _ = C.navigate(&game, mover, .{ .x = 140, .y = 0 }, @src());
+    for (0..20) |_| {
+        C.advance(&game, 0.125); // low frame rate also needs no nearest searches
+        try testing.expect(C.preparedDistance(&game, mover, goal) != null);
+        try testing.expect(C.preparedDistance(&game, carried, goal) != null);
+        const stats = try domainRun(&game, 8);
+        try testing.expectEqual(@as(usize, 0), stats.nearest_searches);
+    }
+    // An external move immediately invalidates; cancellation does not bless it.
+    game.setPosition(mover, .{ .x = 10000 });
+    C.cancel(&game, mover);
+    try testing.expectEqual(null, C.preparedDistance(&game, mover, goal));
+    try testing.expectEqual(null, C.preparedDistance(&game, carried, goal));
+    try testing.expect((try domainRun(&game, 8)).nearest_searches > 0);
+}
+
+test "walker route endpoints remain current on long authored edges and reject graph changes" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const a = node(&game, 0);
+    const b = node(&game, 600);
+    game.addComponent(a, pf.MovementLink{ .dx = 600 });
+    const mover = item(&game, 0);
+    game.addComponent(mover, pf.MovementSpeed{ .speed = 100 });
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 8);
+    _ = C.navigate(&game, mover, .{ .x = 600, .y = 0 }, @src());
+    for (0..4) |_| {
+        C.advance(&game, 1);
+        try testing.expect(C.preparedDistance(&game, mover, b) != null);
+        try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 8)).nearest_searches);
+    }
+    game.setPosition(b, .{ .x = 610 });
+    try testing.expectEqual(null, C.preparedDistance(&game, mover, a));
+}
+
+test "direct walks retain a validated known anchor and dropping invalidates attached items" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const mover = item(&game, 1);
+    const carried = item(&game, 0);
+    game.setParent(carried, mover, .{});
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 8);
+    _ = C.moveTo(&game, mover, .{ .x = 60, .y = 0 });
+    C.advance(&game, 0.125);
+    try testing.expect(C.preparedDistance(&game, mover, n) != null);
+    try testing.expect(C.preparedDistance(&game, carried, n) != null);
+    try testing.expectEqual(@as(usize, 0), (try domainRun(&game, 8)).nearest_searches);
+    game.removeParentKeepTransform(carried);
+    try testing.expectEqual(null, C.preparedDistance(&game, carried, n));
+    _ = try domainRun(&game, 8);
+    try testing.expect(C.preparedDistance(&game, carried, n) != null);
+}

From 2e3d954856b2f399c07009c9d975753d2cb550ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexandre=20Calv=C3=A3o?= <apotema@gmail.com>
Date: Mon, 19 Oct 2026 14:06:08 +0000
Subject: [PATCH 9/9] fix: refresh direct mover anchors and tolerate missing
 registration index

---
 build.zig.zon                          |  2 +-
 src/nav/controller.zig                 | 69 ++++++++++++++++++--------
 tests/integration/preparation_test.zig | 43 ++++++++++++++++
 3 files changed, 91 insertions(+), 23 deletions(-)

diff --git a/build.zig.zon b/build.zig.zon
index 2e11fa6..03f0a74 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -3,7 +3,7 @@
     // v3.0.0 — repurposed: the ECS navigation Controller (promoted from
     // flying-platform) is now the headline API; the standalone algorithm core
     // moves under `.algo`; the old position-owning engine is dropped.
-    .version = "4.3.0-rc.1",
+    .version = "4.3.0-rc.2",
     .fingerprint = 0x15f62ccc39d14685,
     .minimum_zig_version = "0.16.0",
     .dependencies = .{
diff --git a/src/nav/controller.zig b/src/nav/controller.zig
index 4912117..d77aa19 100644
--- a/src/nav/controller.zig
+++ b/src/nav/controller.zig
@@ -856,6 +856,39 @@ pub const Controller = struct {
         return publishEndpointAt(game, st, entity, node, @intCast(node_entity), distance_to_node);
     }
 
+    fn ensureSearchNodes(st: *State) !void {
+        if (st.search_epoch != st.graph_epoch) {
+            st.search_nodes.clearRetainingCapacity();
+            try st.search_nodes.ensureTotalCapacity(st.allocator, st.pf.graph.totalSlots());
+            for (0..st.pf.graph.totalSlots()) |i| {
+                const id: NodeId = @intCast(i);
+                if (st.pf.graph.isRemoved(id)) continue;
+                st.search_nodes.appendAssumeCapacity(.{ .id = id, .entity = st.node_entities.get(id) orelse continue, .position = st.pf.graph.getPosition(id) });
+            }
+            st.search_epoch = st.graph_epoch;
+        }
+    }
+
+    // Direct movers have no graph edge to own. Reuse a proven nearest-node
+    // region, or resolve again at the new position before publishing.
+    fn publishDirectEndpoint(game: anytype, st: *State, entity: anytype) !void {
+        if (!preparedGraphCurrent(game, st)) return;
+        const ecs = &game.active_world.ecs_backend;
+        _ = try game.trackPositionRevision(entity);
+        const stamp = endpointStamp(game, st, entity) orelse return;
+        var cmn = if (ecs.getComponent(entity, ClosestMovementNode)) |old| old.* else ClosestMovementNode{};
+        const pos = game.getWorldPosition(entity);
+        var resolution = reusePreparedResolution(st, &cmn, stamp, pos);
+        if (resolution == null) {
+            try ensureSearchNodes(st);
+            resolution = resolvePreparedNearest(st.search_nodes.items, pos);
+        }
+        if (!cmn.publish(stamp, stamp, resolution)) return;
+        ecs.addComponent(entity, cmn);
+        game.active_world.position_revisions.acknowledge(@intCast(entity), stamp.position_revision);
+        if (resolution) |ready| publishAttachedEndpoints(game, entity, @as(@TypeOf(entity), @intCast(ready.node_entity)));
+    }
+
     fn publishEndpointAt(game: anytype, st: *State, entity: anytype, node: NodeId, node_entity: u64, distance_to_node: f32) !bool {
         const ecs = &game.active_world.ecs_backend;
         _ = try game.trackPositionRevision(entity);
@@ -954,7 +987,11 @@ pub const Controller = struct {
     }
 
     fn registeredIdentity(st: *State, node: NodeId, entity: u64) bool {
-        return node < st.registered_entities.items.len and st.registered_entities.items[node] == entity and !st.pf.graph.isRemoved(node);
+        const registered = if (node < st.registered_entities.items.len)
+            st.registered_entities.items[node] orelse st.node_entities.get(node)
+        else
+            st.node_entities.get(node);
+        return registered == entity and !st.pf.graph.isRemoved(node);
     }
 
     fn preparedEndpointNode(game: anytype, st: *State, entity: anytype) ?NodeId {
@@ -1416,16 +1453,7 @@ pub const Controller = struct {
             st.preparation_stats.pending += 1;
             st.preparation_batch.consider(@intCast(entity));
         }
-        if (st.search_epoch != st.graph_epoch) {
-            st.search_nodes.clearRetainingCapacity();
-            try st.search_nodes.ensureTotalCapacity(st.allocator, st.pf.graph.totalSlots());
-            for (0..st.pf.graph.totalSlots()) |i| {
-                const id: NodeId = @intCast(i);
-                if (st.pf.graph.isRemoved(id)) continue;
-                st.search_nodes.appendAssumeCapacity(.{ .id = id, .entity = st.node_entities.get(id) orelse continue, .position = st.pf.graph.getPosition(id) });
-            }
-            st.search_epoch = st.graph_epoch;
-        }
+        try ensureSearchNodes(st);
         const Entity = @TypeOf(game.*).EntityType;
         // Snapshot every selected entity before searching or publishing any.
         // OOM can register revision tokens, but cannot publish a partial batch.
@@ -1677,12 +1705,13 @@ pub const Controller = struct {
             };
             if (st.preparation_enabled) {
                 const old_len = st.registered_entities.items.len;
-                st.registered_entities.resize(st.allocator, @as(usize, node_id) + 1) catch {
-                    watches_ok = false;
-                    continue;
-                };
-                @memset(st.registered_entities.items[old_len..], null);
-                st.registered_entities.items[node_id] = entity_id;
+                if (st.registered_entities.resize(st.allocator, @as(usize, node_id) + 1)) |_| {
+                    @memset(st.registered_entities.items[old_len..], null);
+                    st.registered_entities.items[node_id] = entity_id;
+                } else |_| {
+                    // Optional fast index: the canonical registration map remains
+                    // usable. Allocation failure must not invalidate graph watches.
+                }
                 st.graph_inputs.put(st.allocator, node_id, .{
                     .position = pos,
                     .stair = is_stair,
@@ -1809,11 +1838,7 @@ pub const Controller = struct {
                 .move => |next| {
                     game.setPosition(entity, next);
                     if (st.preparation_enabled) {
-                        if (ecs.getComponent(entity, ClosestMovementNode)) |cmn| {
-                            const known: Entity = @intCast(cmn.node_entity);
-                            if (publishKnownEndpoint(game, entity, known) catch false)
-                                publishAttachedEndpoints(game, entity, known);
-                        }
+                        publishDirectEndpoint(game, st, entity) catch {};
                     }
                 },
             }
diff --git a/tests/integration/preparation_test.zig b/tests/integration/preparation_test.zig
index 6b51858..806bf45 100644
--- a/tests/integration/preparation_test.zig
+++ b/tests/integration/preparation_test.zig
@@ -803,3 +803,46 @@ test "direct walks retain a validated known anchor and dropping invalidates atta
     _ = try domainRun(&game, 8);
     try testing.expect(C.preparedDistance(&game, carried, n) != null);
 }
+
+test "direct movers switch to nearer nodes before leaving the old snap radius" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    _ = node(&game, 0);
+    const nearer = node(&game, 40);
+    _ = node(&game, 80);
+    const mover = item(&game, 1);
+    const carried = item(&game, 0);
+    game.setParent(carried, mover, .{});
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 8);
+    _ = C.moveTo(&game, mover, .{ .x = 100, .y = 0 });
+    // Default direct speed is 200 px/s: cross the first nearest-node boundary.
+    C.advance(&game, 0.2);
+    const pos = game.getWorldPosition(mover);
+    try testing.expect(pos.x > 20 and pos.x < 60);
+    try testing.expectEqual(@as(u64, @intCast(nearer)), game.getComponent(mover, CMN).?.node_entity);
+    try testing.expectEqual(@as(u64, @intCast(nearer)), game.getComponent(carried, CMN).?.node_entity);
+    try testing.expect(C.endpointPreparationComplete(&game, mover));
+}
+
+test "missing optional registration index preserves prepared queries and graph epoch" {
+    var game = Game.init(testing.allocator);
+    defer game.deinit();
+    const n = node(&game, 0);
+    const mover = item(&game, 1);
+    try setup(&game);
+    defer C.deinit(&game);
+    _ = try domainRun(&game, 8);
+    var view = game.active_world.ecs_backend.view(.{pf.ControllerState}, .{});
+    defer view.deinit();
+    const holder = view.next().?;
+    const state: *pf.controller.State = @ptrFromInt(game.getComponent(holder, pf.ControllerState).?.state_ptr);
+    const epoch = state.graph_epoch;
+    // Same absent-index state as an allocation failure during registration.
+    state.registered_entities.clearRetainingCapacity();
+    try testing.expect(C.preparedDistance(&game, mover, n) != null);
+    C.advance(&game, 0);
+    try testing.expectEqual(epoch, state.graph_epoch);
+    try testing.expect(C.preparedDistance(&game, mover, n) != null);
+}