feat: Improve search config + rename Dashboard + fix SearXNG

SearXNG:
- Fix tini not found error by calling entrypoint.sh directly
- Keep limiter.toml creation at container startup

UI Changes:
- Rename "Tableau de bord" to "Suivis produits" in navigation
- Move CSS selector configuration from item modal to Settings page
- Add price_selector field to search sites configuration
- Display CSS selector badge on site cards

Backend:
- Add price_selector column to SearchSite model and schemas
- Update init.sql with search_sites table and migration for existing DBs

app/models.py

@@ -91,5 +91,6 @@ class SearchSite(Base):
     is_active: bool = Column(Boolean, default=True)  # type: ignore
     priority: int = Column(Integer, default=0)  # type: ignore  # Ordre d'affichage
     requires_js: bool = Column(Boolean, default=False)  # type: ignore  # Force Browserless si True
+    price_selector: str | None = Column(String, nullable=True)  # type: ignore  # Sélecteur CSS pour le prix
     created_at: datetime = Column(DateTime, default=lambda: datetime.now(UTC))  # type: ignore
     updated_at: datetime = Column(DateTime, default=lambda: datetime.now(UTC), onupdate=lambda: datetime.now(UTC))  # type: ignore