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/app/(main)/settings/loading.tsx

@@ -0,0 +1,26 @@
+export default function SettingsLoading() {
+  return (
+    <div className="space-y-6 animate-pulse">
+      <div>
+        <div className="h-9 w-64 bg-muted rounded-md mb-2" />
+        <div className="h-4 w-96 bg-muted rounded-md" />
+      </div>
+      {[1, 2, 3].map((i) => (
+        <div key={i} className="rounded-lg border border-border p-6 space-y-4">
+          <div className="flex items-center gap-3">
+            <div className="h-8 w-8 bg-muted rounded-full" />
+            <div className="h-5 w-40 bg-muted rounded-md" />
+          </div>
+          <div className="h-px bg-border" />
+          <div className="flex items-center justify-between p-4 rounded-lg bg-muted/30">
+            <div className="space-y-2">
+              <div className="h-4 w-32 bg-muted rounded" />
+              <div className="h-3 w-56 bg-muted rounded" />
+            </div>
+            <div className="h-6 w-11 bg-muted rounded-full" />
+          </div>
+        </div>
+      ))}
+    </div>
+  )
+}