feat: prepare mi-fitness-mcp for first public release

Package the standalone Mi Fitness MCP with clearer public docs, release metadata, CI, and safer local repository hygiene so it is ready to publish without secrets or work identity leakage.

.gitignore

@@ -20,6 +20,7 @@ build/
 htmlcov/
 .tox/
 .mypy_cache/
+.ruff_cache/
 .dmypy.json
 *.iml
 .idea/
@@ -27,3 +28,15 @@ htmlcov/
 *.swp
 *.swo
 *~
+
+# Local runtime data
+logs/
+data/
+exports/
+tmp/
+config.json
+*.local.json
+*.sqlite
+*.sqlite-*
+*.db-*
+*.zip