Phase 1.4: Permission Checking Utilities

[bakhterets]

Purpose:
Provide utility functions to check role permissions for actions and resources.

Tasks:

• T004 [P] Create permission checking utility functions in internal/api/auth/rbac.go
  • Implement HasPermission(role, permission) → bool
  • Implement HasRole(role, requiredRole) → bool
  • Implement CanPerformAction(user, action, resource) → bool
  • Definition of Done: Unit tests for each role checking each permission type; tests for role precedence affecting permissions