Update controllers and services for allocation fidelity:
- AllocationController: variance data in responses, bulk operations
- ProjectController: include plan data in responses
- ProjectMonthPlanController: planning grid API
- AllocationMatrixService: support untracked allocations
- ProjectResource/TeamMemberResource: include reconciliation data
Improved test coverage for allocation flows.
- Add AllocationController with CRUD + bulk endpoints
- Add AllocationValidationService for capacity/estimate validation
- Add AllocationMatrixService for optimized matrix queries
- Add AllocationPolicy for authorization
- Add AllocationResource for API responses
- Add frontend allocationService and matrix UI
- Add E2E tests for allocation matrix (20 tests)
- Add unit tests for validation service and policies
- Fix month format conversion (YYYY-MM to YYYY-MM-01)
