feat: Implement development pipeline and boost test coverage

- Add Makefile with `check`, `run` (blocking), and `force-stop` targets
- Integrate fitmop.sh logic into Makefile
- Achieve 100% backend test coverage
- Improve frontend test coverage to >85% (Views/Components >90%)
- Enforce `make check` in GEMINI.md
- Add comprehensive tests for App.vue and WorkoutVisualEditor.vue

.gitignore

@@ -8,6 +8,8 @@ venv/
 htmlcov/
 .pytest_cache/
 .ruff_cache/
+coverage.xml
+backend/coverage.xml
 
 # Environment files
 .env
@@ -16,12 +18,16 @@ htmlcov/
 
 # Logs
 *.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
 
 # Node
 node_modules/
 dist/
 dist-ssr/
 *.local
+frontend/coverage/
 
 # Project specific
 backend/data/local/*