fix(deploy): resolve Docker startup and CSRF issues

- Rename TASKPLANER_DATA_DIR to DATA_DIR (avoid adapter-node envPrefix conflict)
- Add TASKPLANER_ORIGIN for CSRF protection in docker-compose.yml
- Add automatic database schema initialization on startup
- Add Playwright E2E tests for Docker deployment verification
- Update .env.example with correct variable names

Fixes container restart loop and 403 errors on form submission.

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

.planning/phases/06-deployment/06-UAT.md

@@ -0,0 +1,49 @@
+---
+status: complete
+phase: 06-deployment
+source: 06-01-SUMMARY.md, 06-02-SUMMARY.md
+started: 2026-02-01T12:30:00Z
+updated: 2026-02-01T12:30:00Z
+---
+
+## Current Test
+
+[testing complete]
+
+## Tests
+
+### 1. Docker Build Succeeds
+expected: Run `docker compose build` — build completes without errors
+result: pass
+
+### 2. Container Starts and Runs
+expected: Run `docker compose up -d` — container starts, `docker compose ps` shows healthy status
+result: pass
+
+### 3. Application Accessible
+expected: Open http://localhost:3000 in browser — TaskPlanner UI loads, shows entry list
+result: pass
+
+### 4. Health Endpoint Returns 200
+expected: Run `curl http://localhost:3000/health` — returns 200 OK with JSON status
+result: pass
+
+### 5. Data Persists Across Restart
+expected: Create a test entry, run `docker compose restart`, refresh browser — entry still exists
+result: pass
+
+### 6. Backup Script Creates Archive
+expected: Run `./backup.sh` — creates timestamped .tar.gz file in backups/ directory
+result: pass
+
+## Summary
+
+total: 6
+passed: 6
+issues: 0
+pending: 0
+skipped: 0
+
+## Gaps
+
+[none yet]