fix(sync): make transaction creation idempotent (#38)

## Summary
- When a transaction ID is provided during sync, check if it already
exists before creating
- If it exists, return the existing transaction with 200 status instead
of failing with duplicate key error
- Prevents duplicate transactions when sync retries occur due to network
issues

## Test plan
- [x] Attempt to create a transaction with a specific ID
- [x] Attempt to create another transaction with the same ID
- [x] Verify the second request returns the existing transaction instead
of an error

app/Http/Controllers/Sync/TransactionSyncController.php

@@ -36,6 +36,21 @@ class TransactionSyncController extends Controller
         $labelIds = $data['label_ids'] ?? [];
         unset($data['label_ids']);
 
+        // If ID is provided, check if transaction already exists (idempotent create)
+        if (isset($data['id'])) {
+            $existing = Transaction::query()
+                ->where('id', $data['id'])
+                ->where('user_id', $request->user()->id)
+                ->first();
+
+            if ($existing) {
+                // Transaction already exists, return it as success (idempotent)
+                return response()->json([
+                    'data' => $existing->load('labels:id,name,color'),
+                ], 200);
+            }
+        }
+
         // Create transaction with provided ID if available
         $transaction = new Transaction([
             ...$data,

app/Mail/Drip/FeedbackEmail.php

@@ -58,6 +58,6 @@ class FeedbackEmail extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }

app/Mail/Drip/ImportHelpEmail.php

@@ -58,6 +58,6 @@ class ImportHelpEmail extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }

app/Mail/Drip/OnboardingReminderEmail.php

@@ -58,6 +58,6 @@ class OnboardingReminderEmail extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }

app/Mail/Drip/PromoCodeEmail.php

@@ -59,6 +59,6 @@ class PromoCodeEmail extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }

app/Mail/Drip/WelcomeEmail.php

@@ -58,6 +58,6 @@ class WelcomeEmail extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }

app/Mail/UserLeadInvitation.php

@@ -74,6 +74,6 @@ class UserLeadInvitation extends Mailable implements ShouldQueue
      */
     public function middleware(): array
     {
-        return [new RateLimited('emails', releaseAfter: 1)];
+        return [(new RateLimited('emails'))->releaseAfter(1)];
     }
 }