infra: migrate deployment to Coolify with Garage S3

- Remove docker-compose files (Coolify manages services individually)
- Replace MinIO with Garage (S3-compatible, actively maintained)
- Add CI deploy job: build+push :develop image on every green Develop push
- Add Coolify webhook trigger for automatic redeployment
- Update README, .env.example, and storage references
- Rename migrate script to provider-agnostic name

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.example

@@ -1,23 +1,22 @@
 # PostgreSQL
-POSTGRES_PASSWORD=changeme
+DATABASE_URL=postgresql://gearbox:changeme@localhost:5432/gearbox
 
-# Logto OIDC (get from Logto Admin Console at http://localhost:3002)
+# S3-compatible Object Storage (Garage, R2, AWS S3)
+S3_ENDPOINT=http://localhost:3900
+S3_ACCESS_KEY=your-access-key
+S3_SECRET_KEY=your-secret-key
+S3_BUCKET=gearbox-images
+S3_REGION=garage
+# S3_PRESIGN_EXPIRY=3600  # Presigned URL expiry in seconds (default: 1 hour)
+
+# Logto OIDC
 LOGTO_ENDPOINT=http://localhost:3001
-LOGTO_ADMIN_ENDPOINT=http://localhost:3002
-LOGTO_CLIENT_ID=your-app-client-id
-LOGTO_CLIENT_SECRET=your-app-client-secret
-OIDC_AUTH_SECRET=generate-a-random-32-char-string-here
-
-# Derived (set in docker-compose.yml, not needed here):
-# OIDC_ISSUER=${LOGTO_ENDPOINT}/oidc
+OIDC_ISSUER=http://localhost:3001/oidc
+OIDC_CLIENT_ID=your-app-client-id
+OIDC_CLIENT_SECRET=your-app-client-secret
+OIDC_AUTH_SECRET=generate-a-random-32-char-string
+OIDC_SCOPES=openid profile email
+OIDC_REDIRECT_URI=http://localhost:5173/callback
 
 # GearBox
 GEARBOX_URL=http://localhost:3000
-
-# S3-compatible Object Storage (MinIO)
-S3_ENDPOINT=http://localhost:9000
-S3_ACCESS_KEY=minioadmin
-S3_SECRET_KEY=minioadmin
-S3_BUCKET=gearbox-images
-S3_REGION=us-east-1
-# S3_PRESIGN_EXPIRY=3600  # Presigned URL expiry in seconds (default: 1 hour)