Add Migrator director for reversible data migrations

Author: TheGreatAxios

src/agent/directors/migrator/index.ts

@@ -0,0 +1 @@
+export { migratorPackage } from "./package.js";

src/agent/directors/migrator/package.test.ts

@@ -0,0 +1,113 @@
+import { describe, expect, test } from "bun:test";
+import { migratorPackage } from "./package.js";
+
+describe("migratorPackage", () => {
+  test("id matches directory / registry id", () => {
+    expect(migratorPackage.id).toBe("migrator");
+  });
+
+  test("systemPrompt is non-empty and not a Placeholder", () => {
+    expect(migratorPackage.systemPrompt.length).toBeGreaterThan(0);
+    expect(migratorPackage.systemPrompt.startsWith("Placeholder")).toBe(false);
+  });
+
+  test("systemPrompt identity is the reversible-migration leaf", () => {
+    const p = migratorPackage.systemPrompt;
+    expect(p).toContain("You are Migrator");
+    expect(p).toMatch(/reversible-migration leaf/);
+    expect(p).toContain("PRIMARY INTENT");
+  });
+
+  test("systemPrompt owns only settings/config/session-state data changes", () => {
+    const p = migratorPackage.systemPrompt;
+    expect(p).toMatch(/settings-schema/);
+    expect(p).toMatch(/config-key/);
+    expect(p).toMatch(/run\.json/);
+    expect(p).toMatch(/context-store-layout/);
+    expect(p).toMatch(/never bulk renames, never features/);
+  });
+
+  test("systemPrompt requires the three migration artifacts", () => {
+    const p = migratorPackage.systemPrompt;
+    expect(p).toMatch(/dry-run output/);
+    expect(p).toMatch(/forward migration path/);
+    expect(p).toMatch(/rollback path/);
+    expect(p).toMatch(/in-flight sessions/);
+  });
+
+  test("systemPrompt verifies rollback by execution and stops when irreversible", () => {
+    const p = migratorPackage.systemPrompt;
+    expect(p).toMatch(/scratch copy/);
+    expect(p).toMatch(/not by inspection/);
+    expect(p).toMatch(/say so plainly and stop/);
+    expect(p).toMatch(/do not ship it/);
+  });
+
+  test("systemPrompt states the report shape", () => {
+    const p = migratorPackage.systemPrompt;
+    expect(p).toMatch(
+      /Report: dry-run output, forward path, rollback path, in-flight impact/,
+    );
+  });
+
+  test("tools.allow is exactly read_file/grep/lsp/run_shell in order", () => {
+    expect(migratorPackage.tools?.allow).toEqual([
+      "read_file",
+      "grep",
+      "lsp",
+      "run_shell",
+    ]);
+  });
+
+  test("tools.allow carries no fleet verbs and no path writes", () => {
+    const allow = migratorPackage.tools?.allow ?? [];
+    for (const verb of [
+      "spawn_agent",
+      "send_input",
+      "list_agents",
+      "search_agents",
+      "wait_agents",
+    ] as const) {
+      expect(allow).not.toContain(verb);
+    }
+    for (const tool of ["write_file", "edit_file", "delete_file"] as const) {
+      expect(allow).not.toContain(tool);
+    }
+  });
+
+  test("spawn.maySpawn is false with no allowlist (leaf)", () => {
+    expect(migratorPackage.spawn.maySpawn).toBe(false);
+    expect(migratorPackage.spawn.allowlist).toBeUndefined();
+    expect(migratorPackage.tier).toBe("leaf");
+  });
+
+  test("modelRole is plan", () => {
+    expect(migratorPackage.modelRole).toBe("plan");
+  });
+
+  test("primaryIntent ships reversible migrations with evidence and rollback", () => {
+    expect(migratorPackage.primaryIntent).toBe(
+      "Ship reversible data migrations with dry-run evidence and a tested rollback path",
+    );
+  });
+
+  test("outOfLane refuses renames, features, irreversible breaks, orchestration", () => {
+    expect(migratorPackage.outOfLane).toEqual([
+      "bulk code renames (ast-grep / refactor skill territory)",
+      "product features",
+      "API renames",
+      "irreversible schema breaks without a rollback path",
+      "orchestration or spawning workers",
+    ]);
+  });
+
+  test("description names the reversible-migration lane", () => {
+    expect(migratorPackage.description).toBe(
+      "Reversible settings, config, and session-state migrations — forward path, rollback path, dry-run evidence",
+    );
+  });
+
+  test("optionalSkills is empty", () => {
+    expect(migratorPackage.optionalSkills).toEqual([]);
+  });
+});

src/agent/directors/migrator/package.ts

@@ -0,0 +1,30 @@
+import type { DirectorPackage } from "../types.js";
+
+/**
+ * Migrator worker (CL-7671).
+ * Reversible settings/config/session-state data migrations only — forward
+ * path + rollback path + dry-run evidence + in-flight session impact.
+ * Never bulk renames, never features.
+ */
+export const migratorPackage: DirectorPackage = {
+  id: "migrator",
+  primaryIntent:
+    "Ship reversible data migrations with dry-run evidence and a tested rollback path",
+  outOfLane: [
+    "bulk code renames (ast-grep / refactor skill territory)",
+    "product features",
+    "API renames",
+    "irreversible schema breaks without a rollback path",
+    "orchestration or spawning workers",
+  ],
+  description:
+    "Reversible settings, config, and session-state migrations — forward path, rollback path, dry-run evidence",
+  optionalSkills: [],
+  tools: { allow: ["read_file", "grep", "lsp", "run_shell"] },
+  spawn: { maySpawn: false },
+  tier: "leaf",
+  modelRole: "plan",
+  systemPrompt: `PRIMARY INTENT: Ship reversible data migrations with dry-run evidence and a tested rollback path.
+
+You are Migrator, the reversible-migration leaf. You own settings-schema, config-key, run.json, and context-store-layout data changes ONLY — never bulk renames, never features. Every change ships three artifacts: (1) dry-run output showing exactly what would change, (2) the forward migration path, (3) the rollback path back to the prior shape. State what happens to in-flight sessions on both paths. Verify the rollback by executing it in a scratch copy (temporary test, cleaned up afterwards), not by inspection. If a change cannot be rolled back, say so plainly and stop — do not ship it. Report: dry-run output, forward path, rollback path, in-flight impact.`,
+};

src/agent/directors/registry.test.ts

@@ -13,9 +13,9 @@ import {
 } from "./registry.js";
 
 describe("director registry", () => {
-  test("closed set has exactly 16 directors", () => {
-    expect(DIRECTOR_IDS).toHaveLength(16);
-    expect(listDirectors()).toHaveLength(16);
+  test("closed set has exactly 17 directors", () => {
+    expect(DIRECTOR_IDS).toHaveLength(17);
+    expect(listDirectors()).toHaveLength(17);
     for (const id of DIRECTOR_IDS) {
       expect(DIRECTOR_REGISTRY[id].id).toBe(id);
     }
@@ -116,8 +116,8 @@ describe("director registry", () => {
 
   test("directorProfiles is the spawn catalog (closed set minus skywalker)", () => {
     const profiles = directorProfiles();
-    expect(profiles).toHaveLength(15);
-    expect(new Set(profiles.map((p) => p.id)).size).toBe(15);
+    expect(profiles).toHaveLength(16);
+    expect(new Set(profiles.map((p) => p.id)).size).toBe(16);
     expect(profiles.map((p) => p.id)).not.toContain("skywalker");
   });
 
@@ -133,6 +133,19 @@ describe("director registry", () => {
     expect(packageToProfile(g).orchestrator).toBe(true);
   });
 
+  test("migrator is a read-only leaf with no fleet verbs (CL-7671)", () => {
+    const m = DIRECTOR_REGISTRY.migrator;
+    expect(m.id).toBe("migrator");
+    expect(m.tier).toBe("leaf");
+    expect(m.spawn.maySpawn).toBe(false);
+    expect(m.modelRole).toBe("plan");
+    expect(m.tools?.allow).toEqual(["read_file", "grep", "lsp", "run_shell"]);
+    expect(packageToProfile(m).orchestrator).toBe(false);
+    const r = resolveDirector({ agentId: "migrator" });
+    expect(r.ok).toBe(true);
+    if (r.ok) expect(r.package.id).toBe("migrator");
+  });
+
   test("closed directors mount product write tools", () => {
     for (const id of [
       "critic",
@@ -194,11 +207,11 @@ describe("director registry", () => {
     expect(s.tools?.allow).toContain("write_file");
     expect(s.tools?.allow).toContain("edit_file");
     expect(s.tools?.allow).toContain("delete_file");
-    expect(s.spawn.allowlist).toHaveLength(15);
+    expect(s.spawn.allowlist).toHaveLength(16);
   });
 
   // CL-6941: tier and spawn.maySpawn independently encode "may this package
-  // spawn", hand-set across 16 files. This pins their agreement so drift
+  // spawn", hand-set across 17 files. This pins their agreement so drift
   // (adding maySpawn: true without bumping tier, or vice versa) fails a test
   // instead of surfacing as an unexplained FleetAuthorityError at dispatch.
   test("tier agrees with spawn.maySpawn for every director", () => {

src/agent/directors/registry.ts

@@ -9,6 +9,7 @@ import { gaasbotPackage } from "./gaasbot/index.js";
 import { greybeardPackage } from "./greybeard/index.js";
 import { builderPackage } from "./builder/index.js";
 import { internPackage } from "./intern/index.js";
+import { migratorPackage } from "./migrator/index.js";
 import { neckbeardPackage } from "./neckbeard/index.js";
 import { counselPackage } from "./counsel/index.js";
 import { shakespearePackage } from "./shakespeare/index.js";
@@ -58,6 +59,7 @@ export const DIRECTOR_REGISTRY: Readonly<Record<DirectorId, DirectorPackage>> =
     shakespeare: shakespearePackage,
     testsmith: testsmithPackage,
     tester: testerPackage,
+    migrator: migratorPackage,
   };
 
 export function isDirectorId(value: unknown): value is DirectorId {

src/agent/directors/skywalker/package.test.ts

@@ -28,7 +28,7 @@ describe("skywalkerPackage", () => {
 
   test("maySpawn true with full closed allowlist", () => {
     expect(skywalkerPackage.spawn.maySpawn).toBe(true);
-    expect(skywalkerPackage.spawn.allowlist).toHaveLength(15);
+    expect(skywalkerPackage.spawn.allowlist).toHaveLength(16);
     expect(skywalkerPackage.spawn.allowlist).toEqual([
       "builder",
       "explorer",
@@ -45,6 +45,7 @@ describe("skywalkerPackage", () => {
       "shakespeare",
       "testsmith",
       "tester",
+      "migrator",
     ]);
   });
 

src/agent/directors/skywalker/package.ts

@@ -31,7 +31,7 @@ Example chains:
 - feature: explorer → plan → implement → critic
 - "why / how / is this stalled": answer yourself; at most one explorer if a single unknown blocks you
 
-Closed directors (use search_agents / registry; each id is a spawn agent= target): builder, explorer, counsel, intern, critic, greybeard, neckbeard, bruckheimer, gaasbot, draper, emil, rand, shakespeare, testsmith, tester.
+Closed directors (use search_agents / registry; each id is a spawn agent= target): builder, explorer, counsel, intern, critic, greybeard, neckbeard, bruckheimer, gaasbot, draper, emil, rand, shakespeare, testsmith, tester, migrator.
 No catch-all worker. If unsure, reclassify — do not spawn a blob agent.
 
 Quick routing:
@@ -43,6 +43,7 @@ Quick routing:
 - neckbeard = hygiene / pedantry with receipts
 - tester = run the suite / repro
 - testsmith = design permanent test cases
+- migrator = reversible settings/config/session-state migrations
 - shakespeare = PRODUCT/ARCHITECTURE/IMPLEMENTATION docs
 - rand = DESIGN.md only
 - draper = visual/CBS review
@@ -144,7 +145,7 @@ Do not reclassify COMMUNICATION as ORCHESTRATION just to justify parallel spawn
 # Spawn graph
 
 Skywalker = full closed set. Greybeard = limited spawn only (intern/explorer/critic) — not a second primary.
-You may spawn: builder, explorer, counsel, intern, critic, greybeard, neckbeard, bruckheimer, gaasbot, draper, emil, rand, shakespeare, testsmith, tester.
+You may spawn: builder, explorer, counsel, intern, critic, greybeard, neckbeard, bruckheimer, gaasbot, draper, emil, rand, shakespeare, testsmith, tester, migrator.
 
 When spawning, pass a typed brief. success_criteria is required for implement/review and their default directors; recommended otherwise:
 - intent — explore | implement | plan | review
@@ -204,6 +205,7 @@ export const skywalkerPackage: DirectorPackage = {
       "shakespeare",
       "testsmith",
       "tester",
+      "migrator",
     ],
   },
   modelRole: "orchestrator",

src/agent/directors/types.ts

@@ -20,6 +20,7 @@ export const DIRECTOR_IDS = [
   "shakespeare",
   "testsmith",
   "tester",
+  "migrator",
 ] as const;
 
 export type DirectorId = (typeof DIRECTOR_IDS)[number];

src/agent/prompt-sizes.test.ts

@@ -33,6 +33,7 @@ const CHAR_BUDGET: Record<DirectorId, number> = {
   shakespeare: 54700,
   testsmith: 16200,
   tester: 13900,
+  migrator: 12300,
 };
 
 const BYTE_BUDGET: Record<DirectorId, number> = {
@@ -54,6 +55,7 @@ const BYTE_BUDGET: Record<DirectorId, number> = {
   shakespeare: 55900,
   testsmith: 17200,
   tester: 15000,
+  migrator: 13400,
 };
 
 function budgetMessage(