fix: remove deprecated eslint config and make dashboard DB enrichment optional

- Remove unsupported `eslint` key from next.config.ts (Next.js 16)
- Wrap dashboard DB enrichment in try/catch so the dashboard renders
  even when PostgreSQL is unavailable, preventing the
  "Impossible de charger le tableau de bord" error

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

next.config.ts

@@ -10,9 +10,6 @@ const nextConfig = {
   typescript: {
     ignoreBuildErrors: true,
   },
-  eslint: {
-    ignoreDuringBuilds: true,
-  },
 };
 
 export default nextConfig;