chore(infra): port 9000, make help, db skip-check, Vite CSS fix

- Django dev server now runs on :9000 (was :8000)
- `make` without args shows all targets with descriptions
- `make db` skips docker start if :5432 already reachable (nc check)
- `make seed` and `make superuser` added as explicit targets
- vite.config.js: assetFileNames without hash so static/dist/main.css
  matches the {% static 'dist/main.css' %} reference in base.html
  (run `npm run build` once after checkout to regenerate the CSS file)

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

CLAUDE.md

@@ -14,14 +14,17 @@ The authoritative requirements are in `wiki/ProductRequirementsDocument.md`. Tec
 
 ## Entwicklungs-Commands
 
+Run `make` without arguments for a full list with descriptions.
+
 ```bash
-make db           # PostgreSQL via Docker starten (oder infra-postgres-1 verwenden)
-make dev          # Django-Dev-Server (Port 8000)
-make css          # Tailwind CSS im Watch-Modus
+make db           # PostgreSQL starten (Noop wenn :5432 bereits erreichbar)
+make css          # Tailwind CSS Watch-Modus — Terminal A, laufen lassen
+make dev          # Django-Dev-Server auf :9000 — Terminal B
+make seed         # Seed-Daten laden (idempotent)
+make superuser    # Superuser anlegen (einmalig für /admin/)
 make migrate      # Migrations generieren und ausführen
 make test         # pytest ausführen
 make lint         # ruff + mypy
-uv run manage.py test vergabe_teilnahme.apps.<app>   # Einzelne App testen
 uv run pytest vergabe_teilnahme/apps/<app>/tests/    # Einzelne Testdatei
 ```