feat: implement pngx-controller with Gitea CI/CD deployment

- Full FastAPI sync engine: master→replica document sync via paperless REST API
- Web UI: dashboard, replicas, logs, settings (Jinja2 + HTMX + Pico CSS)
- APScheduler background sync, SSE live log stream, Prometheus metrics
- Fernet encryption for API tokens at rest
- pngx.env credential file: written on save, pre-fills forms on load
- Dockerfile with layer-cached uv build, Python healthcheck
- docker-compose with host networking for Tailscale access
- Gitea Actions workflow: version bump, secret injection, docker compose deploy

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,27 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "pngx-controller"
+version = "0.1.0"
+description = "Paperless-ngx Central Sync Controller"
+requires-python = ">=3.11"
+dependencies = [
+    "fastapi>=0.115.0",
+    "uvicorn[standard]>=0.32.0",
+    "sqlmodel>=0.0.22",
+    "apscheduler>=3.10.4",
+    "cryptography>=43.0.0",
+    "httpx>=0.27.0",
+    "jinja2>=3.1.4",
+    "python-multipart>=0.0.12",
+    "prometheus-client>=0.21.0",
+    "aiofiles>=24.1.0",
+]
+
+[project.scripts]
+pngx-controller = "app.main:cli_entry"
+
+[tool.hatch.build.targets.wheel]
+packages = ["app"]