diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 770ce9705..5fe27b90b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -359,10 +359,12 @@ jobs:
       - name: Test
         run: vp run --filter @t3tools/web test --shard ${{ matrix.shard }}/${{ strategy.job-total }}
 
-  # apps/server sets `fileParallelism: false`, so its 239 files run strictly
-  # one at a time. Sharding spreads them over separate runners instead of
-  # separate workers, so no two server test files ever share a machine and the
-  # isolation that flag buys is preserved exactly.
+  # apps/server sets `fileParallelism: false`, so its files run strictly one at
+  # a time. Sharding spreads them over separate runners instead of separate
+  # workers, so no two server test files ever share a machine and the isolation
+  # that flag buys is preserved exactly. Each shard deals every 4th file of the
+  # sorted paths (scripts/lib/spread-shard.ts): about 340 s of tests each, where
+  # three hash slices ran 390–525 s and the heaviest neared the 10-minute limit.
   test_server:
     name: Test Server ${{ matrix.shard }}
     runs-on: ubuntu-latest
@@ -370,7 +372,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shard: [1, 2, 3]
+        shard: [1, 2, 3, 4]
     steps:
       - name: Checkout
         uses: actions/checkout@v6
diff --git a/apps/hq/test/harness/testPostgres.test.ts b/apps/hq/test/harness/testPostgres.test.ts
index 6a3200b32..427d1e17b 100644
--- a/apps/hq/test/harness/testPostgres.test.ts
+++ b/apps/hq/test/harness/testPostgres.test.ts
@@ -94,6 +94,29 @@ it.effect(
     }).pipe(Effect.scoped),
 );
 
+// A pool's close returns before PostgreSQL's backend exits; the template must not race that exit.
+it.live("freezes a database whose closed connection's backend is still exiting", () =>
+  Effect.gen(function* () {
+    const owner = yield* lease;
+    const template = yield* Effect.promise(owner.createDatabase);
+    yield* Effect.scoped(
+      Effect.gen(function* () {
+        const source = yield* connection(template);
+        yield* source.query("CREATE TABLE baseline (value text)");
+        // The backend notices its client left only once this statement ends.
+        yield* Effect.forkDetach(source.query("SELECT pg_sleep(0.5)"));
+        yield* Effect.sleep("50 millis");
+      }),
+    );
+    yield* Effect.promise(() => owner.freezeDatabase(template));
+    const clone = yield* Effect.promise(() => owner.cloneDatabase(template));
+    const copied = yield* connection(clone);
+    assert.deepEqual((yield* copied.query("SELECT to_regclass('baseline')::text AS t")).rows, [
+      { t: "baseline" },
+    ]);
+  }).pipe(Effect.scoped),
+);
+
 it.effect.each(["SIGKILL", "exit"] as const)(
   "reclaims a worker database after %s before the next owner's work",
   (mode) =>
diff --git a/apps/server/vite.config.ts b/apps/server/vite.config.ts
index 755b917a2..2548c3c79 100644
--- a/apps/server/vite.config.ts
+++ b/apps/server/vite.config.ts
@@ -5,6 +5,7 @@ import { defineConfig, mergeConfig } from "vite-plus";
 import baseConfig from "../../vite.config.ts";
 import { loadRepoEnv } from "../../scripts/lib/public-config.ts";
 import packageJson from "./package.json" with { type: "json" };
+import { SpreadShardSequencer } from "../../scripts/lib/spread-shard.ts";
 
 // The bundle used to inline only workspace packages, leaving every third-party
 // runtime dep external. External deps must exist on the real filesystem (the WSL
@@ -86,6 +87,8 @@ export default mergeConfig(
       // The server suite exercises sqlite, git, temp worktrees, and orchestration
       // runtimes heavily. Running files in parallel introduces load-sensitive flakes.
       fileParallelism: false,
+      // CI's shards each take every n-th file, so its slow crew and engine suites never share one.
+      sequence: { sequencer: SpreadShardSequencer },
       // Appended to the root setup, which mergeConfig concatenates.
       setupFiles: ["./src/testUtils/gitConfig.setup.ts"],
       // Server integration tests exercise sqlite, git, and orchestration together.
diff --git a/apps/web/src/components/ui/tooltip.test.tsx b/apps/web/src/components/ui/tooltip.test.tsx
index b9e1a92a8..28ba5e39a 100644
--- a/apps/web/src/components/ui/tooltip.test.tsx
+++ b/apps/web/src/components/ui/tooltip.test.tsx
@@ -137,3 +137,53 @@ describe("tooltip scroll dismissal", () => {
     }
   });
 });
+
+describe("tooltip trigger element", () => {
+  // A chat file link renders a menu button until its open action is known, then a link.
+  it.each([{ area: "inside the conversation" }, { area: "outside the conversation" }])(
+    "$area, a trigger that becomes a link still opens its tooltip on hover",
+    async ({ area }) => {
+      vi.stubGlobal("IS_REACT_ACT_ENVIRONMENT", true);
+      vi.useFakeTimers();
+      const container = document.createElement("div");
+      document.body.append(container);
+      const root = createRoot(container);
+      const tooltip = (link: boolean) => (
+        <Tooltip>
+          <TooltipTrigger
+            delay={50}
+            render={link ? <a href="/workspace/src/summary.ts" /> : <button type="button" />}
+          >
+            summary.ts
+          </TooltipTrigger>
+          <TooltipPopup>/workspace/src/summary.ts</TooltipPopup>
+        </Tooltip>
+      );
+      const render = (link: boolean) =>
+        root.render(
+          area === "inside the conversation" ? (
+            <TooltipScrollDismissArea>{tooltip(link)}</TooltipScrollDismissArea>
+          ) : (
+            tooltip(link)
+          ),
+        );
+      try {
+        await act(async () => render(false));
+        await act(async () => render(true));
+        const trigger = container.querySelector<HTMLAnchorElement>("a")!;
+        await act(async () => {
+          trigger.dispatchEvent(new MouseEvent("mouseover", { bubbles: true }));
+          trigger.dispatchEvent(new MouseEvent("mouseenter"));
+          trigger.dispatchEvent(new MouseEvent("mousemove", { bubbles: true }));
+          await vi.advanceTimersByTimeAsync(60);
+        });
+        expect(openPopupText()).toBe("/workspace/src/summary.ts");
+      } finally {
+        await act(async () => root.unmount());
+        container.remove();
+        vi.useRealTimers();
+        vi.unstubAllGlobals();
+      }
+    },
+  );
+});
diff --git a/apps/web/src/components/ui/tooltip.tsx b/apps/web/src/components/ui/tooltip.tsx
index 67476b2fb..416650714 100644
--- a/apps/web/src/components/ui/tooltip.tsx
+++ b/apps/web/src/components/ui/tooltip.tsx
@@ -1,5 +1,13 @@
 import { Tooltip as TooltipPrimitive } from "@base-ui/react/tooltip";
-import { createContext, use, useEffect, useRef, type ComponentProps, type RefObject } from "react";
+import {
+  createContext,
+  isValidElement,
+  use,
+  useEffect,
+  useRef,
+  type ComponentProps,
+  type RefObject,
+} from "react";
 
 import { isFollowScroll } from "~/lib/followScroll";
 import { cn } from "~/lib/utils";
@@ -71,11 +79,18 @@ function Tooltip<Payload>(props: TooltipPrimitive.Root.Props<Payload>) {
 function TooltipTrigger(props: TooltipPrimitive.Trigger.Props) {
   const hovered = use(TooltipScrollContext);
   const actionsRef = use(TooltipHoverContext);
+  // Base UI binds its hover listeners to the first element it renders; a trigger whose element
+  // changes kind (a file chip's menu button becoming its link) remounts so hover reaches it.
+  const key =
+    isValidElement(props.render) && typeof props.render.type === "string"
+      ? props.render.type
+      : undefined;
   if (!hovered || !actionsRef) {
-    return <TooltipPrimitive.Trigger data-slot="tooltip-trigger" {...props} />;
+    return <TooltipPrimitive.Trigger key={key} data-slot="tooltip-trigger" {...props} />;
   }
   return (
     <TooltipPrimitive.Trigger
+      key={key}
       data-slot="tooltip-trigger"
       {...props}
       onMouseEnter={(event) => {
diff --git a/apps/web/src/index.css b/apps/web/src/index.css
index 937269130..f78e531eb 100644
--- a/apps/web/src/index.css
+++ b/apps/web/src/index.css
@@ -939,11 +939,18 @@ html[data-mobile-composer-route-transition="true"]::view-transition-old(t3-mobil
      the footer's own top padding (pt-1.5, sm:pt-2). */
   .chat-composer-dock {
     --chat-composer-dock-gap: calc(var(--spacing) * 1.5);
-    background: linear-gradient(
-      to bottom,
-      transparent var(--chat-composer-dock-gap),
-      var(--background) var(--chat-composer-dock-gap)
-    );
+  }
+
+  /* A solid layer, not a gradient: Chrome dithers a gradient by its tile's
+     origin, so the footer's colour shifted whenever the history above it was
+     repainted. The dock's stacking context keeps it behind the composer. */
+  .chat-composer-dock::before {
+    pointer-events: none;
+    position: absolute;
+    z-index: -1;
+    inset: var(--chat-composer-dock-gap) 0 0;
+    background: var(--background);
+    content: "";
   }
 
   @media (min-width: 40rem) {
diff --git a/apps/web/test/scenarios/areas/g-outage/dsl.ts b/apps/web/test/scenarios/areas/g-outage/dsl.ts
index 7c729b88b..62206dc4e 100644
--- a/apps/web/test/scenarios/areas/g-outage/dsl.ts
+++ b/apps/web/test/scenarios/areas/g-outage/dsl.ts
@@ -29,7 +29,32 @@ export const givenOutage = Effect.fn("outage.given")(function* () {
 export const stopHq = (s: Scenario) => s.drivers.core.stop;
 
 export const declareNewerProtocol = (s: Scenario) => Effect.sync(() => newerHqProtocol(s.drivers));
-export const endHqSession = (s: Scenario) => Effect.sync(() => endHqStream(s.drivers, 4401));
+/** Ends the tab's HQ session; returns how many HQ sockets had opened before it ended. */
+export const endHqSession = (s: Scenario) =>
+  Effect.sync(() => {
+    const opened = s.drivers.hq.counters.wsOpens;
+    endHqStream(s.drivers, 4401);
+    return opened;
+  });
+/**
+ * The tab, woken by `trigger`, opens a new HQ subscription after `opened` sockets. It is woken
+ * again until it does: a wake before the tab noticed the ending finds nothing to recover.
+ */
+export const resubscribesOnResume = (
+  s: Scenario,
+  trigger: "online" | "focus" | "visibilitychange",
+  opened: number,
+) =>
+  Effect.promise(async () => {
+    for (let look = 0; look < 200; look++) {
+      await s.page.evaluate((trigger) => {
+        (trigger === "visibilitychange" ? document : window).dispatchEvent(new Event(trigger));
+      }, trigger);
+      if (s.drivers.hq.counters.wsOpens > opened) return;
+      await new Promise((resolve) => setTimeout(resolve, 50));
+    }
+    throw new Error("The tab opened no new HQ subscription after its session ended");
+  });
 export const refuseHq = (s: Scenario) => Effect.sync(() => endHqStream(s.drivers, 4403));
 export const resumeTab = (s: Scenario, trigger: "online" | "focus" | "visibilitychange") =>
   Effect.promise(() =>
diff --git a/apps/web/test/scenarios/areas/g-outage/outages.scenario.ts b/apps/web/test/scenarios/areas/g-outage/outages.scenario.ts
index 5d0b7fc66..046daeeb4 100644
--- a/apps/web/test/scenarios/areas/g-outage/outages.scenario.ts
+++ b/apps/web/test/scenarios/areas/g-outage/outages.scenario.ts
@@ -25,6 +25,7 @@ import {
   startHq,
   declareNewerProtocol,
   endHqSession,
+  resubscribesOnResume,
   refuseHq,
   resumeTab,
   hqRefusalShown,
@@ -93,9 +94,10 @@ describe("G: outages, sleep and several tabs", () => {
         yield* s.given.signedIn;
         yield* caughtUp(s, "Shop");
         for (let end = 0; end < 3; end++) {
-          yield* endHqSession(s);
-          yield* s.then.hq.isUnavailable;
-          yield* resumeTab(s, "online");
+          // A renewal within the reconnect grace is not an outage, so the menu says nothing of
+          // the ending; the renewal shows as a new subscription.
+          const opened = yield* endHqSession(s);
+          yield* resubscribesOnResume(s, "online", opened);
           yield* caughtUp(s, "Shop");
         }
         yield* checkpoint(s);
diff --git a/apps/web/test/scenarios/harness/clientClock.ts b/apps/web/test/scenarios/harness/clientClock.ts
index b36f1a53c..22fd3bfd0 100644
--- a/apps/web/test/scenarios/harness/clientClock.ts
+++ b/apps/web/test/scenarios/harness/clientClock.ts
@@ -172,6 +172,10 @@ export function clientClock(page: Page, wallClock?: ScenarioWallClock) {
   };
   return {
     install,
+    /** Whether the page's timers run on this clock: its time moves only when advanced. */
+    get installed() {
+      return installed;
+    },
     advance,
     async advanceStepped(ms: number, options: SteppedAdvanceOptions = {}) {
       if (!installed) throw new Error("Install clientClock before sign-in/navigation");
diff --git a/apps/web/test/scenarios/harness/scenario.ts b/apps/web/test/scenarios/harness/scenario.ts
index 9f7292a9f..1a53df301 100644
--- a/apps/web/test/scenarios/harness/scenario.ts
+++ b/apps/web/test/scenarios/harness/scenario.ts
@@ -5,6 +5,8 @@ import * as Schema from "effect/Schema";
 import type { Page, BrowserContext } from "puppeteer-core";
 import { inject } from "vite-plus/test";
 import { expect } from "@effect/vitest";
+// The policy module alone: the data barrel would put the whole data layer in every scenario's graph.
+import { STREAM_POLICY } from "../../../../../packages/client-runtime/src/data/streamMachine.ts";
 import { HqAttentionScopeValue } from "@t3tools/shared/hqStream";
 import { MateLinkUp, MateOverview } from "@t3tools/shared/mateLink";
 import {
@@ -352,10 +354,20 @@ export const createScenario = Effect.fn("scenarios.create")(function* (
     const then = {
       hq: {
         isUnavailable: Effect.promise(async () => {
-          await page.waitForSelector('[data-zerops-surface="sidebar-hq-outage"]', {
-            visible: true,
-            timeout: 10_000,
-          });
+          const outage = '[data-zerops-surface="sidebar-hq-outage"]';
+          const clock = web.clock(page);
+          // A lost link reads as an outage only once its reconnect grace runs out, counted from
+          // when the tab noticed the loss. On a scenario clock that time passes only when
+          // advanced, so it passes a grace at a time until the tab says so (about 10 s at most).
+          for (let look = 0; clock.installed && look < 40; look++) {
+            const shown = await page
+              .waitForSelector(outage, { visible: true, timeout: 250 })
+              .then(() => true)
+              .catch(() => false);
+            if (shown) return;
+            await clock.advance(STREAM_POLICY.reconnectGraceMs);
+          }
+          await page.waitForSelector(outage, { visible: true, timeout: 10_000 });
         }),
       },
       menu: {
diff --git a/scripts/lib/spread-shard.test.ts b/scripts/lib/spread-shard.test.ts
new file mode 100644
index 000000000..b911963f4
--- /dev/null
+++ b/scripts/lib/spread-shard.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vite-plus/test";
+import { spreadShard } from "./spread-shard.ts";
+
+const files = [
+  "src/zerops/crew/CrewEngine.test.ts",
+  "src/zerops/crew/CrewEngine.lead.test.ts",
+  "src/zerops/crew/CrewEngine.operations.test.ts",
+  "src/zerops/crew/CrewEngine.runs.test.ts",
+  "src/engine/engine.pump.test.ts",
+  "src/engine/engine.sim.test.ts",
+  "src/git/GitManager.test.ts",
+];
+
+describe("spreadShard", () => {
+  it("puts every file in exactly one shard, whatever the order it is given in", () => {
+    const shards = [1, 2, 3].map((index) => spreadShard(files, index, 3));
+    const reversed = [1, 2, 3].map((index) => spreadShard(files.toReversed(), index, 3));
+    expect(shards.flat().toSorted()).toEqual(files.toSorted());
+    expect(reversed).toEqual(shards);
+  });
+
+  // Heavy suites cluster by directory; a contiguous slice gave one shard all of crew's engine files.
+  it("spreads a directory's neighbouring files over different shards", () => {
+    const crew = files.filter((file) => file.startsWith("src/zerops/crew/"));
+    const shardOf = (file: string) =>
+      [1, 2, 3, 4].find((index) => spreadShard(files, index, 4).includes(file));
+    expect(new Set(crew.map(shardOf)).size).toBe(crew.length);
+  });
+});
diff --git a/scripts/lib/spread-shard.ts b/scripts/lib/spread-shard.ts
new file mode 100644
index 000000000..0b8c1a044
--- /dev/null
+++ b/scripts/lib/spread-shard.ts
@@ -0,0 +1,26 @@
+import { BaseSequencer, type TestSpecification } from "vite-plus/test/node";
+
+/**
+ * Shard `index` of `count` (1-based): every `count`-th file of the sorted paths. Slow suites
+ * cluster by directory (a module's engine, its runs, its lead…), so a contiguous slice of files —
+ * Vitest's default — can hand one shard several of them; dealing the sorted list round-robin
+ * spreads a directory's neighbours over every shard.
+ */
+export function spreadShard(
+  files: ReadonlyArray<string>,
+  index: number,
+  count: number,
+): Array<string> {
+  return files.toSorted().filter((_, position) => position % count === index - 1);
+}
+
+/** Vitest's sequencer with {@link spreadShard} in place of its contiguous hash slices. */
+export class SpreadShardSequencer extends BaseSequencer {
+  override async shard(files: Array<TestSpecification>): Promise<Array<TestSpecification>> {
+    const { index, count } = this.ctx.config.shard!;
+    const root = this.ctx.config.root;
+    // Every shard sees the same list, so the path below the root orders it the same on each.
+    const byPath = new Map(files.map((spec) => [spec.moduleId.slice(root.length + 1), spec]));
+    return spreadShard([...byPath.keys()], index, count).map((path) => byPath.get(path)!);
+  }
+}
diff --git a/scripts/test-postgres-supervisor.ts b/scripts/test-postgres-supervisor.ts
index 209a3275c..2493ee3c5 100644
--- a/scripts/test-postgres-supervisor.ts
+++ b/scripts/test-postgres-supervisor.ts
@@ -1,4 +1,4 @@
-// @effect-diagnostics nodeBuiltinImport:off preferSchemaOverJson:off -- standalone host-only test PostgreSQL supervisor.
+// @effect-diagnostics nodeBuiltinImport:off preferSchemaOverJson:off globalDate:off globalTimers:off -- standalone host-only test PostgreSQL supervisor.
 import * as NodeChildProcess from "node:child_process";
 import * as NodeCrypto from "node:crypto";
 import * as NodeFS from "node:fs";
@@ -6,6 +6,7 @@ import * as NodeNet from "node:net";
 import * as NodePath from "node:path";
 import * as NodeReadline from "node:readline";
 import * as NodeURL from "node:url";
+import * as NodeUtil from "node:util";
 import { lifecycleLock, postgresHome } from "./test-postgres.ts";
 
 const pgBinDir = (() => {
@@ -25,6 +26,7 @@ const pgBinDir = (() => {
   return "/opt/homebrew/bin";
 })();
 const data = NodePath.join(postgresHome, "data");
+const execFile = NodeUtil.promisify(NodeChildProcess.execFile);
 const socketPath = NodePath.join(postgresHome, "supervisor.sock");
 const run = (command: string, args: string[]) => {
   const result = NodeChildProcess.spawnSync(NodePath.join(pgBinDir, command), args, {
@@ -145,6 +147,27 @@ async function supervise() {
     };
     const sql = (query: string) =>
       run("psql", [urlOf(port, "postgres"), "-X", "-v", "ON_ERROR_STOP=1", "-Atc", query]);
+    /**
+     * Whether a database's last backend left. A client's close returns before its backend exits
+     * (PostgreSQL's own CREATE DATABASE … TEMPLATE waits for such backends too), so a closed pool
+     * still shows for a moment; a connection held open is still there once the wait ends.
+     */
+    const drained = async (name: string) => {
+      const deadline = Date.now() + 2_000;
+      for (;;) {
+        const { stdout } = await execFile(NodePath.join(pgBinDir, "psql"), [
+          urlOf(port, "postgres"),
+          "-X",
+          "-v",
+          "ON_ERROR_STOP=1",
+          "-Atc",
+          `SELECT count(*) FROM pg_stat_activity WHERE datname = '${name}'`,
+        ]);
+        if (stdout.trim() === "0") return true;
+        if (Date.now() >= deadline) return false;
+        await new Promise((resolve) => setTimeout(resolve, 25));
+      }
+    };
     // A prior supervisor's leases cannot survive its loss. Reclaim its managed databases on start.
     for (const name of sql("SELECT datname FROM pg_database WHERE datname LIKE 'mate_test_%'")
       .trim()
@@ -197,7 +220,12 @@ async function supervise() {
         return name;
       };
       const lines = NodeReadline.createInterface({ input: socket });
+      // One command at a time per lease: the client pairs replies with its requests in order.
+      let queue = Promise.resolve();
       lines.on("line", (command) => {
+        queue = queue.then(() => answer(command));
+      });
+      const answer = async (command: string) => {
         try {
           if (released) return;
           if (command === "own") {
@@ -216,9 +244,7 @@ async function supervise() {
             const name = ownedDatabase(command.slice("freeze ".length));
             // Publication requires a closed migration pool; no writer survives the freeze.
             sql(`ALTER DATABASE ${name} ALLOW_CONNECTIONS false`);
-            if (
-              sql(`SELECT count(*) FROM pg_stat_activity WHERE datname = '${name}'`).trim() !== "0"
-            ) {
+            if (!(await drained(name))) {
               sql(`ALTER DATABASE ${name} ALLOW_CONNECTIONS true`);
               throw new Error("Close database connections before freezing a template");
             }
@@ -241,7 +267,7 @@ async function supervise() {
         } catch (error) {
           socket.write(`${JSON.stringify({ error: String(error) })}\n`);
         }
-      });
+      };
       let released = false;
       const release = async (requested = false) => {
         if (released) return;