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>

docker/garage.toml

@@ -0,0 +1,20 @@
+metadata_dir = "/var/lib/garage/meta"
+data_dir = "/var/lib/garage/data"
+db_engine = "sqlite"
+
+replication_factor = 1
+
+[s3_api]
+s3_region = "garage"
+api_bind_addr = "[::]:3900"
+root_domain = ".s3.garage.localhost"
+
+[s3_web]
+bind_addr = "[::]:3902"
+root_domain = ".web.garage.localhost"
+
+[admin]
+api_bind_addr = "[::]:3903"
+
+[rpc]
+bind_addr = "[::]:3901"