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

.agent/skills/bmad-create-prd/templates/prd-template.md

@@ -1,10 +0,0 @@
----
-stepsCompleted: []
-inputDocuments: []
-workflowType: 'prd'
----
-
-# Product Requirements Document - {{project_name}}
-
-**Author:** {{user_name}}
-**Date:** {{date}}