chore: consolidate .env.example to docker folder only

- Remove root .env.example (now only in docker/ folder)
- Update .gitignore to not track root .env.example
- Keep docker/.env.example as single source of truth

docker-compose.yml

@@ -11,8 +11,6 @@
 # - PostgreSQL database (persistent storage)
 # - Caddy reverse proxy with automatic SSL
 
-version: "3.8"
-
 services:
   # ============================================
   # PostgreSQL Database
@@ -62,14 +60,6 @@ services:
       # Admin emails
       ADMIN_EMAILS: ${ADMIN_EMAILS}
 
-      # S3 Storage configuration
-      STORAGE_ENDPOINT: ${STORAGE_ENDPOINT}
-      STORAGE_REGION: ${STORAGE_REGION:-us-east-1}
-      STORAGE_BUCKET: ${STORAGE_BUCKET}
-      STORAGE_ACCESS_KEY: ${STORAGE_ACCESS_KEY}
-      STORAGE_SECRET_KEY: ${STORAGE_SECRET_KEY}
-      STORAGE_PUBLIC_BASE_URL: ${STORAGE_PUBLIC_BASE_URL}
-
       # Optional settings
       BOT_MAX_PER_USER: ${BOT_MAX_PER_USER:-5}