refactor: SendScheduledWhatsAppJob — drop redundant filtering

Audit item #12. The fan-out job ran an upfront Plan query plus a
per-user tier-name comparison before checking canSendNow('whatsapp').
Both are already covered by canSendNow → canUseChannel + daily-limit
count, so the parent was duplicating filtering work that the child
DispatchUserNotificationJob would do anyway via channelsFor().

Now the parent does only the cheap pre-check (canSendNow) before
dispatching the per-user child job. Iteration uses chunkById(500) to
make the memory bound explicit. Each user remains its own queueable
unit — independent retry, no shared failure mode across the cohort.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Jobs/SendScheduledWhatsAppJob.php

@@ -2,16 +2,18 @@
 
 namespace App\Jobs;
 
-use App\Models\Plan;
 use App\Models\User;
 use App\Models\UserNotificationPreference;
 use App\Services\PlanFeatures;
 use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Foundation\Queue\Queueable;
 
 /**
  * Fan-out job for scheduled WhatsApp updates (morning / evening).
- * Finds all eligible users and dispatches DispatchUserNotificationJob per user.
+ * Dispatches one DispatchUserNotificationJob per eligible user so each
+ * user's send is its own queueable unit (independent retry, no shared
+ * failure mode across the cohort).
  *
  * Scheduled at 07:30 (morning) and 18:00 (evening) via routes/console.php.
  */
@@ -28,36 +30,24 @@ final class SendScheduledWhatsAppJob implements ShouldQueue
     {
         $triggerType = $this->period === 'morning' ? 'scheduled_morning' : 'scheduled_evening';
 
-        // Plans that allow scheduled WhatsApp updates
-        $eligiblePlanNames = Plan::where('active', true)
-            ->where('whatsapp_scheduled_updates', '>', 0)
-            ->pluck('name')
-            ->all();
-
-        if (empty($eligiblePlanNames)) {
-            return;
-        }
-
-        // Users who have whatsapp preference enabled
+        // Candidates: users who have explicitly opted in to WhatsApp.
+        // Per-user tier + daily-limit + scheduled-updates checks happen via
+        // canSendNow('whatsapp'); that single call covers tier eligibility
+        // (canUseChannel) AND today's notification_log count.
         $userIds = UserNotificationPreference::where('channel', 'whatsapp')
             ->where('enabled', true)
             ->distinct()
             ->pluck('user_id');
 
         User::whereIn('id', $userIds)
-            ->each(function (User $user) use ($triggerType, $eligiblePlanNames): void {
-                $features = PlanFeatures::for($user);
-
-                // Skip if their tier isn't eligible or daily limit is hit
-                if (! in_array($features->tier(), $eligiblePlanNames, strict: true)) {
-                    return;
-                }
-
-                if (! $features->canSendNow('whatsapp')) {
-                    return;
+            ->chunkById(500, function (Collection $users) use ($triggerType): void {
+                foreach ($users as $user) {
+                    if (! PlanFeatures::for($user)->canSendNow('whatsapp')) {
+                        continue;
                     }
 
                     DispatchUserNotificationJob::dispatch($user, $triggerType, fuelType: 'all');
+                }
             });
     }
 }