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/rollback-notebooks.ts

@@ -16,7 +16,7 @@
  *   npx tsx scripts/rollback-notebooks.ts --confirm
  */
 
-import { prisma } from '../keep-notes/lib/prisma'
+import { prisma } from '../memento-note/lib/prisma'
 
 interface RollbackStats {
   notebooksDeleted: number