fix(source): scope private key and source selection to current team

The Source component now resolves the supplied private key and Git
source IDs through team-scoped queries before persisting them, so a
selection can only ever reference a resource owned by the current
team. The source type is additionally restricted to the supported
GitHub/GitLab app classes.

The privateKeyId property is marked #[Locked] so it can only change
through the dedicated handler rather than a direct property update.

Adds feature tests covering team-scoped selection of private keys and
Git sources.

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

app/Livewire/Project/Application/Source.php

@@ -3,6 +3,8 @@
 namespace App\Livewire\Project\Application;
 
 use App\Models\Application;
+use App\Models\GithubApp;
+use App\Models\GitlabApp;
 use App\Models\PrivateKey;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Livewire\Attributes\Locked;
@@ -21,7 +23,7 @@ class Source extends Component
     #[Validate(['nullable', 'string'])]
     public ?string $privateKeyName = null;
 
-    #[Validate(['nullable', 'integer'])]
+    #[Locked]
     public ?int $privateKeyId = null;
 
     #[Validate(['required', 'string'])]
@@ -103,7 +105,8 @@ class Source extends Component
     {
         try {
             $this->authorize('update', $this->application);
-            $this->privateKeyId = $privateKeyId;
+            $key = PrivateKey::ownedByCurrentTeam()->findOrFail($privateKeyId);
+            $this->privateKeyId = $key->id;
             $this->syncData(true);
             $this->getPrivateKeys();
             $this->application->refresh();
@@ -136,8 +139,11 @@ class Source extends Component
 
         try {
             $this->authorize('update', $this->application);
+            $allowedSourceTypes = [GithubApp::class, GitlabApp::class];
+            abort_unless(in_array($sourceType, $allowedSourceTypes, true), 404);
+            $source = $sourceType::ownedByCurrentTeam()->findOrFail($sourceId);
             $this->application->update([
-                'source_id' => $sourceId,
+                'source_id' => $source->id,
                 'source_type' => $sourceType,
             ]);