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>

.gitignore

@@ -154,6 +154,7 @@ web_modules/
 
 # dotenv environment variable files
 .env
+.env.coolify-*
 .env.development.local
 .env.test.local
 .env.production.local