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/public/manifest.json

@@ -0,0 +1,23 @@
+{
+  "name": "Memento Notes",
+  "short_name": "Memento",
+  "description": "A smart, local-first note taking app with AI capabilities.",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#f59e0b",
+  "icons": [
+    {
+      "src": "/icons/icon-192.svg",
+      "sizes": "192x192",
+      "type": "image/svg+xml",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/icons/icon-512.svg",
+      "sizes": "512x512",
+      "type": "image/svg+xml",
+      "purpose": "any maskable"
+    }
+  ]
+}