feat: add case tracking model for independent investigation management

[codesailor4]

• Create Case model with ownership and status tracking
• Link InvestigationNote to Case with cascade delete
• Add Case relationship to User model
• Generate migration for cases table and relationships

Description

✅ Implementation Summary

Case Model Created

• id - Unique identifier (CUID)
• title - Case title/name
• ownerId - Ownership tracking (foreign key to User)
• status - Status field with default "open" (supports: open, in_progress, closed, on_hold)
• createdAt & updatedAt - Timestamps for audit trail

Relationships Configured

• User → Case: One-to-many relationship (users can own multiple cases)
• Case → InvestigationNote: One-to-many relationship (notes belong to cases)
• Cascade delete enabled on InvestigationNote (deleting a case removes its notes)

Migration Generated

Located in migration.sql:

• Creates cases table with proper structure and defaults
• Creates index on ownerId for query performance
• Establishes foreign key constraints for data integrity
• Sets up cascade delete for investigation notes

All acceptance criteria met:

• ✅ Case entity created
• ✅ Migration generated
• ✅ Relationships configured with ownership and status tracking

Made changes.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Related Issues

Fixes #
Related to #

Changes Made

Testing

• I have tested these changes locally
• Tests pass locally (npm run test)
• Linting passes (npm run lint)
• Code is formatted (npm run format)
• TypeScript builds successfully (npm run build)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests passed with my changes

Screenshots (if applicable)

Additional Context

Closes #126

[mijinummi]

Hello @codesailor4 , thank you for this great work. Please kindly fix the database migration check failure and push back. Well done