Remove legacy authentication and PostgreSQL configuration

- Remove obsolete auth middleware references from settings and notifications pages
- Clean up .env.example: remove unused PostgreSQL and PostgREST variables
- Delete POSTGRES_SETUP.md: outdated documentation for removed services
- App now uses Supabase directly instead of local PostgreSQL+PostgREST
- Authentication is handled entirely by Authentik Forward Auth at Traefik level

.env.example

@@ -1,20 +1,6 @@
 # Supabase Configuration
 SUPABASE_URL=https://your-project.supabase.co
 SUPABASE_SERVICE_ROLE_KEY=your-service-role-key
-SUPABASE_ANON_KEY=your-anon-key
 
 # Authentik Configuration
 NUXT_PUBLIC_AUTHENTIK_URL=https://authentik.nucleoriofrio.com
-
-# PostgreSQL Configuration
-POSTGRES_USER=postgres
-POSTGRES_PASSWORD=your-secure-password
-POSTGRES_DB=analitica
-
-# PostgREST Configuration
-PGRST_DB_AUTHENTICATOR_PASSWORD=your-authenticator-password
-PGRST_DB_SCHEMA=public
-PGRST_DB_ANON_ROLE=web_anon
-PGRST_JWT_SECRET=your-jwt-secret-min-32-chars
-PGRST_OPENAPI_SERVER_PROXY_URI=https://api.analitica.nucleoriofrio.com
-NUXT_PUBLIC_POSTGREST_URL=https://api.analitica.nucleoriofrio.com