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

packages/config/src/index.ts

@@ -40,6 +40,12 @@ export const EMBED_BASE_URL = process.env.EMBED_BASE_URL ?? "";
 export const EMBED_API_KEY = process.env.EMBED_API_KEY ?? "";
 export const EMBED_MODEL = process.env.EMBED_MODEL ?? "";
 
+// Phase 3: Redis + BullMQ (shared imrnes Redis, no auth by default).
+export const REDIS_URL = process.env.REDIS_URL ?? "redis://100.121.180.82:6379";
+export const REDIS_PASSWORD = process.env.REDIS_PASSWORD ?? "";
+// BullMQ key prefix to namespace jobs on the shared Redis instance.
+export const QUEUE_PREFIX = process.env.QUEUE_PREFIX ?? "mcpedia";
+
 if (!DATABASE_URL) {
   // Fail fast with an explicit message instead of a cryptic driver error.
   throw new Error(