build: align Dockerfile with packer build and add docker-compose dev mounts

- Rebase Dockerfile onto almalinux9-base, install via uv tool install
- Remove dev artifacts (remotes.yaml, ca-bundle.pem) from image
- Mount gitignored dev files via docker-compose volumes instead
- Add .dockerignore to keep secrets out of build context
- Add pre-commit hook to validate docker build on Dockerfile changes
- Track docker-compose.yml in git (no secrets; dev files mounted as volumes)

.gitignore

@@ -59,5 +59,4 @@ uv.lock
 minio_data/
 
 # Local configuration overrides
-docker-compose.yml
 ca-bundle.pem