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

requirements.txt

@@ -0,0 +1,2 @@
+pyinstaller
+windows-curses; sys_platform == 'win32'