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/hooks/use-debounce.ts

@@ -0,0 +1,17 @@
+import { useEffect, useState } from 'react';
+
+export function useDebounce<T>(value: T, delay: number): T {
+  const [debouncedValue, setDebouncedValue] = useState<T>(value);
+
+  useEffect(() => {
+    const timer = setTimeout(() => {
+      setDebouncedValue(value);
+    }, delay);
+
+    return () => {
+      clearTimeout(timer);
+    };
+  }, [value, delay]);
+
+  return debouncedValue;
+}