* Introduce project_personas table with foreign keys to projects and agent_personas
* Add project_skills table with foreign key to projects and agent_skills
* Include override boolean field in agent_persona_skills and project_skills
* Update schema and migration files to reflect new tables and fields
* Enhance CORS handling to reflect request origin
- Created tables for agent_personas, agent_parts, agent_traits, and character_arcs.
- Established relationships between personas, parts, skills, guardrails, and traits.
- Added arc stages and their corresponding parts, along with a persona_arc table to track current stages.
- Implemented cascading delete rules for referential integrity.