Add Python/FastAPI + PostgreSQL backend (Phase 1)

- server/: FastAPI app with SQLAlchemy models for sops, work_packages, comments
- Endpoints for SOP/WP upsert+list+get+delete and comment create+list;
  /api/feedback kept as an alias so the existing client keeps working
- Portable across engines (PostgreSQL prod, SQLite dev fallback)
- requirements.txt, .env.example, and server/README.md (Postgres + systemd)
- NGINX now proxies /api/ to the API (replaces the Power Automate hop;
  comments persist to SQL)
- Rewrite DEPLOYMENT.md for the API + database architecture
- Add .gitignore for venv/.env/sqlite

Phase 2 (wire the client apps to the API) is next.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,13 @@
+# Python
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+*.egg-info/
+
+# Local env / secrets
+.env
+
+# Local SQLite dev database
+*.db
+wpsuite.db