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>

.gitignore

@@ -29,3 +29,10 @@ data/*.db-shm
 data/attachments/*
 !data/.gitkeep
 !data/attachments/.gitkeep
+
+# Backups
+backups/
+
+# Playwright
+playwright-report/
+test-results/