🧹 Clean up repository: Remove NPM and reference documentation

- Removed INSTALLATION_GUIDE.md (NPM-specific)
- Removed NPM_PUBLISHING_GUIDE.md (NPM-specific)
- Removed NPM_PACKAGE_REPORT.md (reference only)
- Removed figma-docs/ directory (reference only)

Keep repo focused on core Agentwise functionality.

Author: VibeCodingWithPhil