fix(git-sync): address PR #119 review #2 — throttle /git Basic auth, fix mcp schema drift + warnings/tests

Must-fix:
- Throttle the raw /git HTTP-Basic path: it bypasses Nest/ThrottlerGuard, so
  verifyUserCredentials (bcrypt) ran unthrottled. Wrap it in the SAME
  FailedLoginLimiter the /mcp path uses (5/60s; per-IP, per-IP+email, global
  per-email keys; atomic tryReserve BEFORE bcrypt; success resets, non-credential
  errors release). The (threshold+1)-th attempt now gets 429 pre-bcrypt. Sweep
  timer + onModuleDestroy mirror McpService.
- Fix the mcp schema mirror drift: packages/mcp details `open` attr now reads via
  hasAttribute (matches editor-ext canon + git-sync copy); getAttribute dropped a
  bare `<details open>` state. (build/ is gitignored — rebuilt locally.)

Tests added:
- /git brute-force throttle: pre-bcrypt 429 on the 6th failure; success resets;
  non-credential error releases the budget.
- git-http-backend lost-lock AbortSignal: already-aborted -> no spawn + 500;
  live abort mid-request -> SIGTERM + response closed.
- orchestrator divergentDocmost -> WARN + flag surfaced in status (+ clean case).
- pollTick re-entrancy guard skips an overlapping tick.
- datasource NotFound early-throws (getPageJson/move/rename) + updatedAt:undefined
  stale-read branch (importPageMarkdown/createPage).

Suggestions:
- space.repo updateGitSyncSettings: parameterize the jsonb key (`${prefKey}::text`)
  instead of sql.raw (latent-injection footgun); value stays sql.lit. Spec updated.
- pollTick re-entrancy guard (private `polling` flag).
- page-change.listener docstring: honest about the move/rename/delete over-skip
  (loop-guard keys only on lastUpdatedSource) -> ~poll-interval latency, not loss.
- AGENTS.md: document the root /git smart-HTTP route + GitSyncModule.
- Remove redundant redteam-provenance.spec.ts (covered e2e in
  persistence.extension.spec.ts:145).
- Extract the duplicated SIGTERM->SIGKILL+finish block (watchdog + abort) into
  terminateChild; centralize watchdog-timer teardown in done().

Architecture (deferred, documented): mcp schema header now carries the three-copy
keep-in-sync + schema-core note; the editor-ext contract test documents that the
mcp copy and attribute-behaviour drift (details `open`) are not mechanically
covered yet.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/integrations/git-sync/http/git-http-backend.service.spec.ts

@@ -251,6 +251,45 @@ describe('GitHttpBackendService.run', () => {
     expect(res.statusCode).toBe(500);
     expect(res.end).toHaveBeenCalledWith('Internal server error');
   });
+
+  it('(abort) an ALREADY-aborted signal -> no spawn, 500 lock-lost', async () => {
+    // The per-space lock was already lost before run() reached the spawn: we must
+    // NOT start writing the working tree after a possible lock takeover.
+    const child = fakeChild();
+    spawnMock.mockReturnValue(child);
+    const service = buildService();
+    const res = fakeRes();
+
+    const controller = new AbortController();
+    controller.abort();
+    await service.run(baseRequest, fakeReq(), res, controller.signal);
+
+    expect(spawnMock).not.toHaveBeenCalled();
+    expect(res.statusCode).toBe(500);
+    expect(res.end).toHaveBeenCalledWith('Internal server error');
+  });
+
+  it('(abort) a live signal aborted mid-request -> child SIGTERM + response closed', async () => {
+    // The lock lapses mid-push: the abort fires, the child is killed (SIGTERM,
+    // then SIGKILL on escalation), and the response is finished.
+    const child = fakeChild();
+    spawnMock.mockReturnValue(child);
+    const service = buildService();
+    const res = fakeRes();
+    const warnSpy = jest.spyOn(Logger.prototype, 'warn');
+
+    const controller = new AbortController();
+    const p = service.run(baseRequest, fakeReq(), res, controller.signal);
+    await flush(); // let run() reach the spawn + wire the abort listener
+    controller.abort();
+    await p;
+
+    expect(child.kill).toHaveBeenCalledWith('SIGTERM');
+    expect(warnSpy).toHaveBeenCalled();
+    // No headers were sent before the abort -> a clean 500 is sent and ended.
+    expect(res.statusCode).toBe(500);
+    expect(res.writableEnded).toBe(true);
+  });
 });
 
 describe('buildGitBackendCgiEnv', () => {