V2 project update

[locnguyen1986]

Project Feature Implementation Summary

Completed ✅

1. Domain Layer - services/llm-api/internal/domain/project/

   • ✅ project.go - Project entity, repository interface, NewProject factory
   • ✅ project_validation.go - Validation logic (name ≤ 120 chars, instruction ≤ 32k)
   • ✅ project_service.go - Business logic service

2. Database Schema - services/llm-api/internal/infrastructure/database/dbschema/

   • ✅ project.go - GORM schema with EtoD/DtoE converters, auto-migration registered
   • ✅ conversation.go - Updated with ProjectID, InstructionVersion, EffectiveInstructionSnapshot

3. Repository Layer - services/llm-api/internal/infrastructure/database/repository/projectrepo/

   • ✅ project_repository.go - CRUD operations with soft-delete, pagination support

4. HTTP DTOs

   • ✅ requests/projectreq/requests.go - CreateProjectRequest, UpdateProjectRequest
   • ✅ responses/projectres/responses.go - ProjectResponse, ProjectListResponse, ProjectDeletedResponse

5. Conversation Domain Updates

   • ✅ Added ProjectID, InstructionVersion, EffectiveInstructionSnapshot fields
   • ✅ Updated NewConversation to initialize instruction fields