fix(gh-aw): align squad-cast history.json playbook with validator and add skill-discovery fallback (#2474)

The squad-cast playbook told the agent to initialize .squad/casting/history.json
with assigned_at/agent_count and empty assignment_cast_snapshots, which
squad-cast-validator.mjs rejects (used_at, a cast-revision-1 snapshot stamped
with registry.generated_at, and no transaction_id/registry_revision are required).
Every first /squad cast therefore failed with "universe usage history is
malformed" and cascaded into specialists=0 false positives.

- Replace the Step 3 history.json example with a validator-passing fresh-Cast
  example and spell out the schema rules.
- Add an Execute Mode fallback: when the skill tool reports "Skill not found"
  (headless SDK sessions), read .github/skills/<name>/SKILL.md from disk.
- Add a drift test that extracts the playbook example, pairs it with a matching
  revision-1 registry, and runs it through the validators; also asserts the
  package copy carries the identical example.
- Regenerate workflows/package/squad.md and manifest digests.

Fixes #2473

Co-authored-by: Copilot <Copilot@users.noreply.github.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: 3 people

test/gh-aw-cast-validator.test.ts

@@ -691,6 +691,53 @@ describe('GH-AW Cast final-tree validator', () => {
     expect(result.status, result.stderr).toBe(0);
   });
 
+  it('accepts the fresh-Cast history.json example shipped in the squad-cast playbook', async () => {
+    const extractExample = (source: string): string => {
+      const match = source.match(
+        /<!-- SQUAD:CAST-HISTORY-EXAMPLE:BEGIN -->\r?\n\s*```json\r?\n([\s\S]*?)\r?\n\s*```\r?\n\s*<!-- SQUAD:CAST-HISTORY-EXAMPLE:END -->/,
+      );
+      if (!match) throw new Error('squad-cast playbook history.json example markers are missing');
+      return match[1].split(/\r?\n/).map(line => line.trim()).join('\n');
+    };
+    const example = extractExample(readFileSync(workflowPath, 'utf8'));
+    expect(extractExample(readFileSync(join(process.cwd(), 'workflows', 'package', 'squad.md'), 'utf8'))).toBe(example);
+
+    const history = JSON.parse(example) as {
+      universe_usage_history: Array<{ universe: string; used_at: string }>;
+      assignment_cast_snapshots: Record<string, { created_at: string; universe: string; agents: string[] }>;
+    };
+    expect(Object.keys(history.assignment_cast_snapshots)).toEqual(['cast-revision-1']);
+    const snapshot = history.assignment_cast_snapshots['cast-revision-1'];
+    expect(snapshot.agents).toEqual(active.map(({ id }) => id));
+    expect(history.universe_usage_history).toEqual([{ universe: snapshot.universe, used_at: snapshot.created_at }]);
+
+    const fixture = createFixture();
+    write(fixture.root, '.squad/casting/registry.json', JSON.stringify({
+      schema: 'squad-agent-provenance/v1',
+      schema_version: 1,
+      revision: 1,
+      generated_at: snapshot.created_at,
+      agents: Object.fromEntries(active.map(({ id, name, role }) => [
+        id,
+        {
+          display_name: name,
+          persistent_name: name,
+          role,
+          status: 'active',
+          universe: snapshot.universe,
+          created_at: '2026-09-20T00:00:00.000Z',
+          updated_at: snapshot.created_at,
+        },
+      ])),
+    }));
+    write(fixture.root, '.squad/casting/history.json', example);
+    const registryFile = join(fixture.root, '.squad', 'casting', 'registry.json');
+
+    await expect(validateCastingPairFiles(registryFile)).resolves.toMatchObject({ revision: 1 });
+    const result = validateWorkflowResource(fixture.root, fixture.payload);
+    expect(result.status, result.stderr).toBe(0);
+  });
+
   it.each([
     {
       name: 'revision-2 registry with unrelated empty history',

workflows/package/squad.md

@@ -2290,7 +2290,9 @@ Each mode's playbook ships as a **skill**. Enter this section only after **Actor
 
 **Planning modes only** — before running the mode skill, also load `squad-planning-policy` (policy resolution) and `squad-planning-ontology` (artifact schemas and the lifecycle state machine). The non-planning modes (Cast, Connect, Adopt, Cast Member, Retire, Status, Review Relay, Approve Improvement, Revoke Improvement, Implement) must not load them.
 
-If the parsed mode's skill cannot be loaded, report the failure in plain language and stop. Never improvise a mode playbook from memory.
+**Skill discovery fallback:** if the `skill` tool reports `Skill not found` for a skill listed above (headless SDK sessions may not register workspace skills), read the installed copy `.github/skills/<skill-name>/SKILL.md` from the workspace with `bash` (`cat`) and follow that file verbatim as the playbook. Apply the same fallback to `squad-planning-policy` and `squad-planning-ontology`. Do not `report_incomplete` or stop solely because the skill tool is not registered.
+
+If the parsed mode's skill cannot be loaded by either path, report the failure in plain language and stop. Never improvise a mode playbook from memory.
 
 ---
 
@@ -2495,7 +2497,24 @@ Guidelines: 4–7 active agents. Min: Lead + 2 specialists + 1 quality role.
    - Descriptive mode: keep names role-derived, short, and unique; do not assign fictional character names.
    - Themed modes: use one universe only, pressure/function over authority, no spoilers, and early-introduction names. For a custom universe, apply the same one-universe and spoiler-safety rules.
 4. Write `.squad/casting/registry.json` as `squad-agent-provenance/v1`. Compare the committed registry: preserve every ID/tombstone, immutable role/creation time, and avatar unless explicitly cleared; set `revision` greater than the committed revision (legacy is 0). Keys are immutable IDs/directories. Records hold equal names, role, universe, lifecycle/status, and optional ID-owned avatar under `.squad/agents/{id}/`. Rename uses the existing ID; deletion tombstones; never reuse or infer IDs. In descriptive mode every registry entry has `universe` set to `"descriptive"`.
-5. Initialize `.squad/casting/history.json`: `{ "universe_usage_history": [{ "universe": "descriptive-or-Universe", "assigned_at": "ISO", "agent_count": N }], "assignment_cast_snapshots": {} }`
+5. Write `.squad/casting/history.json` so it passes the deterministic Cast validator (`squad-cast-validator.mjs`), replacing the disposable activation preset file entirely. For a fresh Cast (`revision: 1`) the file must contain exactly one usage record and one snapshot keyed `cast-revision-1`; `used_at` and `created_at` must both equal the registry `generated_at`; `universe` must match the registry (`"descriptive"` in descriptive mode); `agents` must list every registry agent ID; and the only top-level fields are `universe_usage_history` and `assignment_cast_snapshots` — never carry over `transaction_id`, `registry_revision`, `assigned_at`, or `agent_count`. Example for a registry with `generated_at` `2026-09-21T00:00:00.000Z` and agents `lead`, `builder`, `tester`:
+   <!-- SQUAD:CAST-HISTORY-EXAMPLE:BEGIN -->
+   ```json
+   {
+     "universe_usage_history": [
+       { "universe": "descriptive", "used_at": "2026-09-21T00:00:00.000Z" }
+     ],
+     "assignment_cast_snapshots": {
+       "cast-revision-1": {
+         "created_at": "2026-09-21T00:00:00.000Z",
+         "universe": "descriptive",
+         "agents": ["lead", "builder", "tester"]
+       }
+     }
+   }
+   ```
+   <!-- SQUAD:CAST-HISTORY-EXAMPLE:END -->
+   For a re-Cast at revision N, append one `cast-revision-N` snapshot and one usage record (both stamped with the new `generated_at`) to the committed history instead of rewriting it.
 
 ##### Step 4: Generate Scaffolding
 

workflows/squad-workflows.manifest.json

@@ -15,9 +15,9 @@
       "source": "workflows/package/squad.md",
       "destination": ".github/workflows/squad.md",
       "lock": ".github/workflows/squad.lock.yml",
-      "source_sha256": "b3e9b33c8ddbf578e277d036c21ea5d1a5136cd234aa6b153627dc5f345bbf3d",
-      "lock_sha256": "36e56e20eedb07007d81a64ebcae38fffe7441c69ff0dbc792048ea9c5576e48",
-      "package_lock_sha256": "f744139e41ce8667555d8b6508b30391d4bf2a142bbefc85e418035c95c7dd97"
+      "source_sha256": "f145131ddebed1f9e96d9d3f7b344b3137bbc4fc93c6c3aa5b60fce4d0393c38",
+      "lock_sha256": "9eb9a91fd119f3a9847d57856376e973031bfc38aea4a1df95b825a3de5cd663",
+      "package_lock_sha256": "2eaae88e8fc4ccc7c3a4dd12edd7e30e1cb63179bd085a18cb273e99a6bc963d"
     },
     {
       "name": "squad-implement-worker",
@@ -89,8 +89,8 @@
       "workflows": [
         {
           "name": "squad",
-          "lock_sha256": "36e56e20eedb07007d81a64ebcae38fffe7441c69ff0dbc792048ea9c5576e48",
-          "package_lock_sha256": "f744139e41ce8667555d8b6508b30391d4bf2a142bbefc85e418035c95c7dd97"
+          "lock_sha256": "9eb9a91fd119f3a9847d57856376e973031bfc38aea4a1df95b825a3de5cd663",
+          "package_lock_sha256": "2eaae88e8fc4ccc7c3a4dd12edd7e30e1cb63179bd085a18cb273e99a6bc963d"
         },
         {
           "name": "squad-implement-worker",

workflows/squad.md

@@ -1087,7 +1087,9 @@ Each mode's playbook ships as a **skill**. Enter this section only after **Actor
 
 **Planning modes only** — before running the mode skill, also load `squad-planning-policy` (policy resolution) and `squad-planning-ontology` (artifact schemas and the lifecycle state machine). The non-planning modes (Cast, Connect, Adopt, Cast Member, Retire, Status, Review Relay, Approve Improvement, Revoke Improvement, Implement) must not load them.
 
-If the parsed mode's skill cannot be loaded, report the failure in plain language and stop. Never improvise a mode playbook from memory.
+**Skill discovery fallback:** if the `skill` tool reports `Skill not found` for a skill listed above (headless SDK sessions may not register workspace skills), read the installed copy `.github/skills/<skill-name>/SKILL.md` from the workspace with `bash` (`cat`) and follow that file verbatim as the playbook. Apply the same fallback to `squad-planning-policy` and `squad-planning-ontology`. Do not `report_incomplete` or stop solely because the skill tool is not registered.
+
+If the parsed mode's skill cannot be loaded by either path, report the failure in plain language and stop. Never improvise a mode playbook from memory.
 
 ---
 
@@ -1292,7 +1294,24 @@ Guidelines: 4–7 active agents. Min: Lead + 2 specialists + 1 quality role.
    - Descriptive mode: keep names role-derived, short, and unique; do not assign fictional character names.
    - Themed modes: use one universe only, pressure/function over authority, no spoilers, and early-introduction names. For a custom universe, apply the same one-universe and spoiler-safety rules.
 4. Write `.squad/casting/registry.json` as `squad-agent-provenance/v1`. Compare the committed registry: preserve every ID/tombstone, immutable role/creation time, and avatar unless explicitly cleared; set `revision` greater than the committed revision (legacy is 0). Keys are immutable IDs/directories. Records hold equal names, role, universe, lifecycle/status, and optional ID-owned avatar under `.squad/agents/{id}/`. Rename uses the existing ID; deletion tombstones; never reuse or infer IDs. In descriptive mode every registry entry has `universe` set to `"descriptive"`.
-5. Initialize `.squad/casting/history.json`: `{ "universe_usage_history": [{ "universe": "descriptive-or-Universe", "assigned_at": "ISO", "agent_count": N }], "assignment_cast_snapshots": {} }`
+5. Write `.squad/casting/history.json` so it passes the deterministic Cast validator (`squad-cast-validator.mjs`), replacing the disposable activation preset file entirely. For a fresh Cast (`revision: 1`) the file must contain exactly one usage record and one snapshot keyed `cast-revision-1`; `used_at` and `created_at` must both equal the registry `generated_at`; `universe` must match the registry (`"descriptive"` in descriptive mode); `agents` must list every registry agent ID; and the only top-level fields are `universe_usage_history` and `assignment_cast_snapshots` — never carry over `transaction_id`, `registry_revision`, `assigned_at`, or `agent_count`. Example for a registry with `generated_at` `2026-09-21T00:00:00.000Z` and agents `lead`, `builder`, `tester`:
+   <!-- SQUAD:CAST-HISTORY-EXAMPLE:BEGIN -->
+   ```json
+   {
+     "universe_usage_history": [
+       { "universe": "descriptive", "used_at": "2026-09-21T00:00:00.000Z" }
+     ],
+     "assignment_cast_snapshots": {
+       "cast-revision-1": {
+         "created_at": "2026-09-21T00:00:00.000Z",
+         "universe": "descriptive",
+         "agents": ["lead", "builder", "tester"]
+       }
+     }
+   }
+   ```
+   <!-- SQUAD:CAST-HISTORY-EXAMPLE:END -->
+   For a re-Cast at revision N, append one `cast-revision-N` snapshot and one usage record (both stamped with the new `generated_at`) to the committed history instead of rewriting it.
 
 ##### Step 4: Generate Scaffolding