fix(runtime): re-point #4058's new /ai/agents assertion at the enveloped body

Semantic conflict, not a textual one. #4058 step 2 (#4086) landed on main while
this branch was open and added `http-dispatcher.test.ts`'s "a stub slot 404s per
route and keeps the /ai/agents empty list", which asserts the body is exactly
`{ agents: [] }` — the shape #4053 enveloped one commit earlier. The two merge
cleanly and the test fails, which is why CI caught it and the merge did not.

The courtesy that test pins is unchanged: a stub-occupied AI slot still answers an
empty list rather than a fault. The list just travels under `data` now, and the
assertion says so — plus that no `agents` key survives at the top level, so a
revert to the bare body fails here too.

Also swept the repo for any other reader of the old shape. Three hits, all
correct: the two negative assertions above, and `client/src/index.ts`'s
`body?.agents` — which is exactly what the relocation variant keeps working.

Merged main in rather than rebasing, per the branch's history so far.

Verified against the full suite the way Test Core runs it —
`turbo run test --filter='!@objectstack/dogfood'`: 129/129 packages, runtime 924.

Two worktree-staleness traps on the way, both reading as code failures:

  - `plugin-auth` could not resolve `hono` — the merge moved the lockfile and I
    had not reinstalled. `pnpm install --frozen-lockfile` fixed it.
  - `runtime` failed under turbo but passed standalone — the gitignored
    `.objectstack/data/memory-driver.json` accumulating rows again.

Neither is CI-visible; CI installs clean and checks out fresh.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CYbS3kS8xzsHNXFTzp4e2z

Author: claude

packages/runtime/src/http-dispatcher.test.ts

@@ -2523,7 +2523,14 @@ describe('HttpDispatcher', () => {
             const agents = await dispatcher.handleAI('/ai/agents', 'GET', undefined, {}, { request: {} });
             expect(agents.handled).toBe(true);
             expect(agents.response?.status).toBe(200);
-            expect(agents.response?.body).toEqual({ agents: [] });
+            // #4053 enveloped this body while #4058 was in flight. The courtesy
+            // this test pins is unchanged — an empty list rather than a fault —
+            // it just travels under `data` now. `AiAgentsResponseSchema`'s
+            // `{ agents }` is RELOCATED, not flattened to the bare array, so
+            // `client.ai.agents.list()` still reads `.agents` off what
+            // `unwrapResponse` returns.
+            expect(agents.response?.body).toEqual({ success: true, data: { agents: [] }, meta: undefined });
+            expect(agents.response?.body?.agents).toBeUndefined();
         });
 
         // Discovery must say exactly what the domains do — one predicate feeds