feat(ci): add Docker build, push and SSH deploy pipeline

- CI: lint, unit tests, production build on all branches
- Docker build & push on all branches (tag :latest on main, :branch-* on others)
- Deploy: SSH pull & restart on all branches (preprod validation)
- Trigger workflow on self-modification (.github/workflows/ui.yml)

Closes #38

Assisted-by: Claude:claude-sonnet-4-6

.gitignore

@@ -3,6 +3,10 @@
 .vscode
 .idea
 
+# Local
+.claude/
+.DS_Store
+
 # Secrets
 **/secrets/
 **/.env