feat(k8s): Add StatefulSet for persistent workers

- Add scraper-worker-statefulset.yaml with 8 persistent pods
- updateStrategy: OnDelete prevents automatic restarts
- Workers maintain stable identity across restarts
- Document worker architecture in CLAUDE.md
- Add worker registry API endpoint documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -205,6 +205,58 @@ These binaries mimic real browser TLS fingerprints to avoid detection.
 
 ---
 
+## Worker Architecture (Kubernetes)
+
+### Persistent Workers (StatefulSet)
+
+Workers run as a **StatefulSet** with 8 persistent pods. They maintain identity across restarts.
+
+**Pod Names**: `scraper-worker-0` through `scraper-worker-7`
+
+**Key Properties**:
+- `updateStrategy: OnDelete` - Pods only update when manually deleted (no automatic restarts)
+- `podManagementPolicy: Parallel` - All pods start simultaneously
+- Workers register with their pod name as identity
+
+**K8s Manifest**: `backend/k8s/scraper-worker-statefulset.yaml`
+
+### Worker Lifecycle
+
+1. **Startup**: Worker registers in `worker_registry` table with pod name
+2. **Preflight**: Runs dual-transport preflights (curl + http), reports IPs and fingerprint
+3. **Task Loop**: Polls for tasks, executes them, reports status
+4. **Shutdown**: Graceful 60-second termination period
+
+### NEVER Restart Workers Unnecessarily
+
+**Claude must NOT**:
+- Restart workers unless explicitly requested
+- Use `kubectl rollout restart` on workers
+- Use `kubectl set image` on workers (this triggers restart)
+
+**To update worker code** (only when user authorizes):
+1. Build and push new image with version tag
+2. Update StatefulSet image reference
+3. Manually delete pods one at a time when ready: `kubectl delete pod scraper-worker-0 -n dispensary-scraper`
+
+### Worker Registry API
+
+**Endpoint**: `GET /api/worker-registry/workers`
+
+**Response Fields**:
+| Field | Description |
+|-------|-------------|
+| `pod_name` | Kubernetes pod name |
+| `worker_id` | Internal worker UUID |
+| `status` | active, idle, offline |
+| `curl_ip` | IP from curl preflight |
+| `http_ip` | IP from Puppeteer preflight |
+| `preflight_status` | pending, passed, failed |
+| `preflight_at` | Timestamp of last preflight |
+| `fingerprint_data` | Browser fingerprint JSON |
+
+---
+
 ## Documentation
 
 | Doc | Purpose |