chore: clean up repo for public release

- Remove BMAD framework, IDE configs, dev screenshots, test files,
  internal docs, and backup files
- Rename keep-notes/ to memento-note/
- Update all references from keep-notes to memento-note
- Add Apache 2.0 license with Commons Clause (non-commercial restriction)
- Add clean .gitignore and .env.docker.example

memento-note/components/debug-theme.tsx

@@ -0,0 +1,9 @@
+'use client'
+
+export function DebugTheme({ theme }: { theme: string }) {
+    return (
+        <div className="fixed bottom-4 left-4 z-50 bg-black text-white p-2 rounded text-xs opacity-80 pointer-events-none">
+            Debug Theme: {theme}
+        </div>
+    )
+}