feat(api): enrich TimeSlotResource with shift statistics

Add shifts_count, total_slots, filled_slots, and sections_count computed
fields to TimeSlotResource. Update TimeSlotController to eager-load shifts
with assignment counts for aggregate calculations. Includes test verifying
only approved assignments count towards filled_slots.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/Http/Controllers/Api/V1/TimeSlotController.php

@@ -20,11 +20,24 @@ final class TimeSlotController extends Controller
     {
         Gate::authorize('viewAny', [TimeSlot::class, $event]);
 
-        $timeSlots = $event->timeSlots()->orderBy('date')->orderBy('start_time')->get();
+        $timeSlots = $event->timeSlots()
+            ->withCount('shifts')
+            ->with(['shifts' => fn ($q) => $q->withCount([
+                'shiftAssignments as assignments_count' => fn ($q) => $q->where('status', 'approved'),
+            ])])
+            ->orderBy('date')
+            ->orderBy('start_time')
+            ->get();
 
         if ($event->isSubEvent() && request()->boolean('include_parent') && $event->parent_event_id) {
             $parentTimeSlots = TimeSlot::where('event_id', $event->parent_event_id)
-                ->with('event')
+                ->withCount('shifts')
+                ->with([
+                    'event',
+                    'shifts' => fn ($q) => $q->withCount([
+                        'shiftAssignments as assignments_count' => fn ($q) => $q->where('status', 'approved'),
+                    ]),
+                ])
                 ->orderBy('date')
                 ->orderBy('start_time')
                 ->get();

api/app/Http/Resources/Api/V1/TimeSlotResource.php

@@ -23,6 +23,21 @@ final class TimeSlotResource extends JsonResource
             'duration_hours' => $this->duration_hours,
             'source' => $this->resource->getAttribute('source'),
             'event_name' => $this->whenLoaded('event', fn () => $this->event->name),
+            'shifts_count' => $this->whenCounted('shifts'),
+            // Aggregates computed from eager-loaded shifts with assignment counts.
+            // For events with >200 shifts, consider replacing with a raw aggregate query.
+            'total_slots' => $this->when(
+                $this->relationLoaded('shifts'),
+                fn () => (int) $this->shifts->sum('slots_total'),
+            ),
+            'filled_slots' => $this->when(
+                $this->relationLoaded('shifts'),
+                fn () => (int) $this->shifts->sum(fn ($shift) => $shift->assignments_count ?? 0),
+            ),
+            'sections_count' => $this->when(
+                $this->relationLoaded('shifts'),
+                fn () => $this->shifts->pluck('festival_section_id')->unique()->count(),
+            ),
             'created_at' => $this->created_at->toIso8601String(),
         ];
     }

api/tests/Feature/TimeSlot/TimeSlotTest.php

@@ -5,7 +5,11 @@ declare(strict_types=1);
 namespace Tests\Feature\TimeSlot;
 
 use App\Models\Event;
+use App\Models\FestivalSection;
 use App\Models\Organisation;
+use App\Models\Person;
+use App\Models\Shift;
+use App\Models\ShiftAssignment;
 use App\Models\TimeSlot;
 use App\Models\User;
 use Database\Seeders\RoleSeeder;
@@ -52,6 +56,59 @@ class TimeSlotTest extends TestCase
         $this->assertCount(3, $response->json('data'));
     }
 
+    public function test_index_includes_shift_statistics(): void
+    {
+        $timeSlot = TimeSlot::factory()->create(['event_id' => $this->event->id]);
+
+        $sectionA = FestivalSection::factory()->create(['event_id' => $this->event->id]);
+        $sectionB = FestivalSection::factory()->create(['event_id' => $this->event->id]);
+
+        $person = Person::factory()->create(['event_id' => $this->event->id]);
+
+        $shift1 = Shift::factory()->create([
+            'festival_section_id' => $sectionA->id,
+            'time_slot_id' => $timeSlot->id,
+            'slots_total' => 5,
+        ]);
+        $shift2 = Shift::factory()->create([
+            'festival_section_id' => $sectionB->id,
+            'time_slot_id' => $timeSlot->id,
+            'slots_total' => 3,
+        ]);
+
+        // Create 2 approved assignments on shift1
+        ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift1->id,
+            'person_id' => $person->id,
+            'time_slot_id' => $timeSlot->id,
+        ]);
+        ShiftAssignment::factory()->approved()->create([
+            'shift_id' => $shift1->id,
+            'person_id' => Person::factory()->create(['event_id' => $this->event->id])->id,
+            'time_slot_id' => $timeSlot->id,
+        ]);
+
+        // Create 1 pending assignment on shift2 (should NOT count towards filled_slots)
+        ShiftAssignment::factory()->create([
+            'shift_id' => $shift2->id,
+            'person_id' => $person->id,
+            'time_slot_id' => $timeSlot->id,
+            'status' => 'pending_approval',
+        ]);
+
+        Sanctum::actingAs($this->orgAdmin);
+
+        $response = $this->getJson("/api/v1/events/{$this->event->id}/time-slots");
+
+        $response->assertOk();
+
+        $data = $response->json('data.0');
+        $this->assertEquals(2, $data['shifts_count']);
+        $this->assertEquals(8, $data['total_slots']);
+        $this->assertEquals(2, $data['filled_slots']);
+        $this->assertEquals(2, $data['sections_count']);
+    }
+
     public function test_store_creates_time_slot(): void
     {
         Sanctum::actingAs($this->orgAdmin);