[Feature] Document Version History and Templates System

[P4ST4S]

Description:
Users cannot save multiple versions of their CGU, compare changes, or create reusable templates. Once generated, documents have no versioning or edit history.

Context/Rationale:
Businesses need to track changes to their legal documents for compliance and auditing. Version history allows users to see what changed and when. Templates let users quickly generate similar documents without re-entering all data. This is essential for professional SaaS.

Implementation Suggestion / To-Do:

1. Create document versioning system with timestamps
2. Implement diff view to compare versions
3. Add ability to restore previous versions
4. Build template creation and management UI
5. Allow users to save custom templates with pre-filled fields
6. Add template sharing for Enterprise tier
7. Implement document forking/cloning