feat(#462): add federation list verb

docs/scratchpads/FED-M3-05-list-verb.md

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+# FED-M3-05 — Federation List Verb Scratchpad
+
+## Objective
+
+Implement `POST /api/federation/v1/list/:resource`.
+
+## Scope
+
+- Wire `FederationAuthGuard` → `FederationScopeService` → read-only list query layer.
+- Apply `max_rows_per_query` row cap and return pagination metadata when truncated.
+- Tag returned rows with `_source: "local"`.
+- Keep audit writes deferred to M4.
+- No request/response body persistence.
+
+## Base / branch
+
+- Branch: `feat/federation-m3-verb-list`
+- Base: `feat/federation-m3-scope-service` (PR #672), per orchestrator, because M3-04 is not merged yet.
+- Rebase target after #672 merges: `main`.
+
+## Implementation notes
+
+- Added `ListController` under `apps/gateway/src/federation/server/verbs/`.
+- Added `FederationListQueryService` as the read-only query layer and native RBAC evaluator.
+- Query resources supported in M3 list path:
+  - `tasks`: project/mission scoped tasks visible through personal/team project access.
+  - `notes`: non-empty `mission_tasks.notes` rows visible through personal/team mission access.
+  - `memory`: user-owned `insights` and `preferences` rows.
+  - `credentials` / `api_keys`: denied by native RBAC in M3 even if present in scope; sensitive-resource implementation is not part of FED-M3-05.
+- Cursor pagination uses an opaque base64url keyset cursor over `(createdAt, id)`; DB reads fetch at most `limit + 1` rows per resource query.
+
+## Tests
+
+- `pnpm --filter @mosaicstack/gateway test -- list.controller.spec.ts list-query.service.spec.ts` — PASS (9 tests).
+- `pnpm --filter @mosaicstack/gateway typecheck` — PASS.
+- `pnpm --filter @mosaicstack/gateway lint` — PASS.
+- `pnpm format:check` — PASS.
+- `pnpm typecheck` — PASS (41/41 turbo tasks).
+- `pnpm lint` — PASS (23/23 turbo tasks).
+- `pnpm --filter @mosaicstack/gateway test` — FAIL in pre-existing/live-DB integration suite: `apps/gateway/src/__tests__/cross-user-isolation.test.ts` cleanup cannot connect to local PostgreSQL on `localhost:5433`. New list tests pass; failure is outside FED-M3-05.
+
+## Review evidence
+
+- `~/.config/mosaic/tools/codex/codex-code-review.sh --uncommitted` — PASS after remediation; approve, no findings.
+- `~/.config/mosaic/tools/codex/codex-security-review.sh --uncommitted` — PASS after cursor remediation; risk level none, no findings.
+- Security-review note: read-path audit logging remains intentionally deferred to M4 per orchestrator clarification and FED-M3-05 scope.
+
+## Risks / follow-up
+
+- This branch intentionally includes M3-04 diff until PR #672 lands; final PR must be rebased onto main after #672 merges.
+- Current branch base predates the M3-07 capabilities module registration; expect a small `FederationModule` rebase conflict once #672 and #674 are both on main.