Move trace project to root and rebrand from fnote

- Move all project files from `trace/` subdirectory to the repository root
- Rename directory structure from `fnote` to `trace`
- Update package references and imports (fnote -> trace)
- Update application branding and storage paths (~/.trace)
- Update build script and documentation
- Ensure __pycache__ is ignored

.gitignore

@@ -0,0 +1,28 @@
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+.Python
+env/
+venv/
+.env
+.venv
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+.pytest_cache/
+.coverage
+htmlcov/
+*.spec