Initial commit: SejeteralO water tarification platform

Full-stack app for participatory water pricing using Bezier curves.
- Backend: FastAPI + SQLAlchemy + SQLite with JWT auth
- Frontend: Nuxt 4 + TypeScript with interactive SVG editor
- Math engine: cubic Bezier tarification with Cardano solver
- Admin: commune management, household import, vote monitoring, CMS
- Citizen: interactive curve editor, vote submission
- Docker-compose deployment ready

Includes fixes for:
- Impact table snake_case/camelCase property mismatch
- CMS content backend API + frontend editor (was stub)
- Admin route protection middleware
- Public content display on commune page
- Vote confirmation page link fix

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

backend/app/config.py

@@ -0,0 +1,19 @@
+from pydantic_settings import BaseSettings
+from pathlib import Path
+
+
+class Settings(BaseSettings):
+    APP_NAME: str = "SejeteralO"
+    DEBUG: bool = True
+    DATABASE_URL: str = "sqlite+aiosqlite:///./sejeteralo.db"
+    SECRET_KEY: str = "change-me-in-production-with-a-real-secret-key"
+    ALGORITHM: str = "HS256"
+    ADMIN_TOKEN_EXPIRE_HOURS: int = 24
+    CITIZEN_TOKEN_EXPIRE_HOURS: int = 4
+    BASE_DIR: Path = Path(__file__).resolve().parent.parent
+    CORS_ORIGINS: list[str] = ["http://localhost:3000", "http://localhost:3001", "http://localhost:3009"]
+
+    model_config = {"env_file": ".env", "env_file_encoding": "utf-8"}
+
+
+settings = Settings()