feat(deploy): add Gitea registry publish script and pull-based compose

- scripts/publish.ps1: build image and push to git.azuze.fr/kawa/imptune
- docker-compose.yml: reference published image (build kept for local builds)
- docker-compose.override.yml: gitignored live-reload dev config
- add .gitignore (override + Python/data artifacts)
- README: document dev vs published-image run and publishing

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,17 @@
+# Local dev compose overrides (personal / per-machine)
+docker-compose.override.yml
+
+# Python
+__pycache__/
+*.py[cod]
+.pytest_cache/
+.mypy_cache/
+.ruff_cache/
+*.egg-info/
+.venv/
+venv/
+
+# Local data / build artifacts
+/data/
+imptune_data/
+*.intunewin