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

scripts/verify-migration.js

@@ -1,4 +1,4 @@
-const { PrismaClient } = require('../keep-notes/prisma/client-generated');
+const { PrismaClient } = require('../memento-note/prisma/client-generated');
 const prisma = new PrismaClient();
 
 (async () => {