feat(allocation): implement resource allocation feature

- 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)

backend/app/Policies/AllocationPolicy.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace App\Policies;
+
+use App\Models\Allocation;
+use App\Models\User;
+
+class AllocationPolicy
+{
+    /**
+     * Determine whether the user can view any allocations.
+     */
+    public function viewAny(User $user): bool
+    {
+        return true;
+    }
+
+    /**
+     * Determine whether the user can view a specific allocation.
+     */
+    public function view(User $user, Allocation $allocation): bool
+    {
+        return true;
+    }
+
+    /**
+     * Determine whether the user can create allocations.
+     */
+    public function create(User $user): bool
+    {
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can update allocations.
+     */
+    public function update(User $user, Allocation $allocation): bool
+    {
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can delete allocations.
+     */
+    public function delete(User $user, Allocation $allocation): bool
+    {
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+}