feat(mcpedia): Phase 3 — async indexing (BullMQ), git-sync webhook, revisions, MCP Resources

- packages/queue: ioredis singleton + BullMQ Queue/Worker (prefix mcpedia:
  on shared imrnes Redis :6379); apps/worker runs startWorker()
- @mcpedia/core: indexContentFile/runFullIndex (single indexing entry point
  shared by script/worker/hook) + revision.service (list/get/restore)
- document_revisions table (migration 0002) — snapshots only on body change
- apps/api: POST /hooks/reindex + /hooks/index webhooks; tRPC revisions,
  getRevision, restoreRevision, jobStatus, queueStatus
- apps/mcp: register MCP Resources mcpedia://docs{/,+slug/chunks/revisions}
  ({+slug} RFC6570 reserved expansion for slugs containing /)
- apps/mcp zod pinned to ^4 to match MCP SDK 1.30 compiled types
  (resolves registerTool TS2589/ShapeOutput skew)
- scripts/enqueue.ts one-shot job enqueue helper; indexer refactored to runFullIndex
- PHASES.md/README/.env.example/docs updated

PHASES.md

@@ -27,12 +27,50 @@ Legend: ✅ built · 🟡 partial · ⬜ deferred
 - [x] MCP server — added `semantic_search` + `hybrid_search` tools (6 total).
 - [x] Web search — keyword/hybrid toggle (`?mode=hybrid`), hybrid reaches semantically-related docs keyword misses.
 
-## Phase 3 — Async + Scale
+## Phase 3 — Async + Scale ✅ DONE
 
-- [ ] Redis + BullMQ background indexing / embedding workers
-- [ ] Git synchronization hook (auto-reindex on push)
-- [ ] Document revision system (`document_revisions`)
-- [ ] MCP Resources (`mcpedia://docs/...`) in addition to tools
+- [x] **Redis + BullMQ background indexing / embedding workers** —
+  `packages/queue` (ioredis singleton + BullMQ `Queue`/`Worker`, prefix
+  `mcpedia:` on shared imrnes Redis `:6379`); `apps/worker` runs
+  `startWorker()`. Three job types: `index-doc`, `index-all`, `reindex`.
+  Single indexing entry point `indexContentFile`/`runFullIndex` in
+  `@mcpedia/core` shared by the script, worker, and git hook. Verified
+  end-to-end against live Redis (job enqueue → worker → Postgres write).
+- [x] **Git synchronization hook (auto-reindex on push)** — API webhook
+  `POST /hooks/reindex` (full) and `POST /hooks/index?slug=` (single) enqueue
+  BullMQ jobs. Wire a Git provider (GitHub/Gitea) post-receive / webhook to
+  `POST /hooks/reindex` to auto-reindex on push. `scripts/enqueue.ts` is a
+  one-shot enqueue helper (`bun run enqueue --all` / `<slug>`).
+- [x] **Document revision system (`document_revisions`)** — `packages/db`
+  migration `0002_document_revisions.sql`. Indexer snapshots a revision only
+  when the body actually changes vs the latest revision (pure metadata edits
+  don't bloat history). `listRevisions` / `getRevision` / `restoreRevision`
+  in `@mcpedia/core`; exposed as tRPC `revisions` / `getRevision` /
+  `restoreRevision` and the `mcpedia://docs/{+slug}/revisions` MCP Resource.
+- [x] **MCP Resources (`mcpedia://docs/...`)** — alongside the 6 tools:
+  `mcpedia://docs` (list), `mcpedia://docs/{+slug}` (body from disk),
+  `mcpedia://docs/{+slug}/chunks` (chunk preview),
+  `mcpedia://docs/{+slug}/revisions` (history). `{+slug}` uses RFC 6570
+  reserved expansion so slugs containing `/` match.
+
+### New/changed commands
+```
+bun run index            # full reindex (runFullIndex, writes revisions)
+bun run enqueue --all    # enqueue a full reindex job (no worker needed)
+bun run enqueue <slug>   # enqueue a single-doc reindex job
+bun run worker           # start the BullMQ indexing worker (long-running)
+bun run api              # Hono+tRPC API on :4020 (added /hooks/* webhooks)
+```
+
+### Verification done (real, against imrnes Redis + Postgres)
+- `turbo run typecheck` green across all 13 packages.
+- BullMQ e2e: enqueue `index-doc` → worker completes → `documents` +
+  `document_chunks` + `document_revisions` rows present.
+- Revision dedup proven: editing a body creates a new revision; metadata-only
+  reindex does not; `restoreRevision` writes history back into the live row.
+- MCP smoke test passes (tools + all 4 resources).
+- API webhook `POST /hooks/reindex` enqueues → worker drains queue →
+  `queueStatus` reflects counts.
 
 ## Phase 4 — Scale-out (only if needed)