fix: batch automation rule application (#435)

## Sentry
- Issue: PHP-LARAVEL-2C
- URL: https://whisper-money.sentry.io/issues/122336983/

## Root cause
Applying an automation rule to multiple transactions used
per-transaction `saveQuietly()` and `syncWithoutDetaching()`. Sentry
detected repeated transaction updates and pivot lookups/inserts on
`/settings/automation-rules/{automationRule}/apply`.

## Fix
- Added batched automation rule application for transaction collections.
- Bulk updates category changes in one query.
- Bulk inserts missing label pivots with `insertOrIgnore`.
- Reused batching from sync controller path and queued job chunks.

## Verification
- `vendor/bin/pint --dirty --format agent`
- `php artisan test --compact
tests/Feature/AutomationRuleApplicationTest.php`

app/Http/Controllers/Settings/AutomationRuleApplicationController.php

@@ -96,8 +96,6 @@ class AutomationRuleApplicationController extends Controller
         }
 
         if ($total <= self::SYNC_THRESHOLD) {
-            $changed = 0;
-
             $transactions = Transaction::query()
                 ->where('user_id', $automationRule->user_id)
                 ->whereIn('id', $matchingIds)
@@ -105,11 +103,7 @@ class AutomationRuleApplicationController extends Controller
                 ->with(['account.bank', 'category', 'labels'])
                 ->get();
 
-            foreach ($transactions as $transaction) {
-                if ($service->applyRuleActions($transaction, $automationRule)) {
-                    $changed++;
-                }
-            }
+            $changed = $service->applyRuleActionsToTransactions($transactions, $automationRule);
 
             $applied = $transactions->count();
 

app/Jobs/ApplySingleAutomationRuleJob.php

@@ -46,14 +46,11 @@ class ApplySingleAutomationRuleJob implements ShouldQueue
             ->whereNull('description_iv')
             ->with(['account.bank', 'category', 'labels'])
             ->chunkById(100, function ($transactions) use ($service, $rule, $total, &$processed, &$applied, &$changed) {
-                foreach ($transactions as $transaction) {
-                    if ($service->applyRuleActions($transaction, $rule)) {
-                        $changed++;
-                    }
-                    $applied++;
-                    $processed++;
-                    $this->updateProgress(status: 'processing', processed: $processed, total: $total, applied: $applied, updated: $changed);
-                }
+                $changed += $service->applyRuleActionsToTransactions($transactions, $rule);
+                $applied += $transactions->count();
+                $processed += $transactions->count();
+
+                $this->updateProgress(status: 'processing', processed: $processed, total: $total, applied: $applied, updated: $changed);
             });
 
         $this->updateProgress(status: 'done', processed: $processed, total: $total, applied: $applied, updated: $changed);

app/Services/AutomationRuleService.php

@@ -3,8 +3,11 @@
 namespace App\Services;
 
 use App\Models\AutomationRule;
+use App\Models\LabelTransaction;
 use App\Models\Transaction;
+use Illuminate\Database\Eloquent\Collection as EloquentCollection;
 use Illuminate\Support\Collection;
+use Illuminate\Support\Str;
 use JWadhams\JsonLogic;
 
 class AutomationRuleService
@@ -57,14 +60,82 @@ class AutomationRuleService
     }
 
     /**
-     * Apply a single rule's actions to the transaction, ignoring rule
-     * priority and other rules. The transaction must already match the rule.
-     *
-     * Returns true if any attribute of the transaction was changed.
+     * @param  EloquentCollection<int, Transaction>  $transactions
      */
-    public function applyRuleActions(Transaction $transaction, AutomationRule $rule): bool
+    public function applyRuleActionsToTransactions(EloquentCollection $transactions, AutomationRule $rule): int
     {
-        return $this->applyActions($transaction, $rule);
+        if ($transactions->isEmpty()) {
+            return 0;
+        }
+
+        $rule->loadMissing('labels');
+        $transactions->loadMissing('labels');
+
+        $changedTransactionIds = [];
+
+        if ($rule->action_category_id !== null) {
+            $categoryTransactionIds = $transactions
+                ->filter(fn (Transaction $transaction): bool => $transaction->category_id !== $rule->action_category_id)
+                ->pluck('id')
+                ->all();
+
+            if ($categoryTransactionIds !== []) {
+                Transaction::query()
+                    ->whereIn('id', $categoryTransactionIds)
+                    ->update([
+                        'category_id' => $rule->action_category_id,
+                        'updated_at' => now(),
+                    ]);
+
+                foreach ($categoryTransactionIds as $transactionId) {
+                    $changedTransactionIds[$transactionId] = true;
+                }
+            }
+        }
+
+        if ($rule->action_note && $rule->action_note_iv === null) {
+            foreach ($transactions as $transaction) {
+                $existingNotes = $transaction->notes ?? '';
+
+                if ($this->noteAlreadyPresent($existingNotes, $rule->action_note)) {
+                    continue;
+                }
+
+                $transaction->notes = $existingNotes
+                    ? $existingNotes."\n".$rule->action_note
+                    : $rule->action_note;
+                $transaction->saveQuietly();
+                $changedTransactionIds[$transaction->id] = true;
+            }
+        }
+
+        $labelIds = $rule->labels->pluck('id')->all();
+        if ($labelIds !== []) {
+            $now = now();
+            $labelTransactionRows = [];
+
+            foreach ($transactions as $transaction) {
+                $transactionLabelIds = $transaction->labels->pluck('id')->all();
+                $missingLabelIds = array_diff($labelIds, $transactionLabelIds);
+
+                foreach ($missingLabelIds as $labelId) {
+                    $labelTransactionRows[] = [
+                        'id' => (string) Str::uuid(),
+                        'label_id' => $labelId,
+                        'transaction_id' => $transaction->id,
+                        'created_at' => $now,
+                        'updated_at' => $now,
+                    ];
+                    $changedTransactionIds[$transaction->id] = true;
+                }
+            }
+
+            if ($labelTransactionRows !== []) {
+                LabelTransaction::query()->insertOrIgnore($labelTransactionRows);
+            }
+        }
+
+        return count($changedTransactionIds);
     }
 
     /**

tests/Feature/AutomationRuleApplicationTest.php

@@ -189,6 +189,52 @@ test('apply endpoint runs synchronously when matches are below threshold', funct
     )->toBe(3);
 });
 
+test('apply endpoint batches category and label writes', function () {
+    Queue::fake();
+
+    $label = Label::factory()->create(['user_id' => $this->user->id]);
+    $this->rule->labels()->attach($label);
+
+    Transaction::factory()->enableBanking()->count(5)->create([
+        'user_id' => $this->user->id,
+        'account_id' => $this->account->id,
+        'category_id' => null,
+        'description' => 'Grocery Store',
+        'amount' => -1000,
+    ]);
+
+    $queries = [];
+    DB::listen(function ($query) use (&$queries): void {
+        $queries[] = $query->sql;
+    });
+
+    $response = $this->actingAs($this->user)
+        ->postJson(route('automation-rules.apply', $this->rule), [
+            'only_uncategorized' => true,
+        ]);
+
+    $transactionUpdateQueries = collect($queries)
+        ->filter(fn (string $query): bool => str_contains($query, 'update "transactions" set')
+            || str_contains($query, 'update `transactions` set'));
+    $perTransactionPivotLookupQueries = collect($queries)
+        ->filter(fn (string $query): bool => (str_contains($query, 'from "label_transaction"')
+            || str_contains($query, 'from `label_transaction`'))
+            && (str_contains($query, '"label_transaction"."transaction_id" =')
+                || str_contains($query, '`label_transaction`.`transaction_id` =')));
+
+    $response->assertOk()
+        ->assertJsonPath('status', 'done')
+        ->assertJsonPath('applied', 5)
+        ->assertJsonPath('updated', 5)
+        ->assertJsonPath('total', 5);
+
+    expect($transactionUpdateQueries)->toHaveCount(1)
+        ->and($perTransactionPivotLookupQueries)->toHaveCount(0);
+
+    Queue::assertNothingPushed();
+    $this->assertDatabaseCount('label_transaction', 5);
+});
+
 test('apply endpoint queues a job when matches exceed threshold', function () {
     Queue::fake();