test(post): cover all 4 terminal statuses on MCP update + API update

UpdatePost::execute returns Finalized for Published, PartiallyPublished,
Failed, and Publishing — the four "terminal" states the PR introduced.
The existing tests for UpdatePostTool (MCP) and Api/PostController only
exercised the Published path. Convert both to a Pest dataset over all
four statuses so a future regression that lets one state slip through
the check fails loudly.

Same shape already used for PublishPostTool and App/PostController.

tests/Feature/Api/PostApiTest.php

@@ -196,11 +196,11 @@
         ->assertNotFound();
 });
 
-it('cannot update published post', function () {
+it('cannot update post in any terminal state', function (PostStatus $status) {
     $post = Post::factory()->create([
         'workspace_id' => $this->workspace->id,
         'user_id' => $this->user->id,
-        'status' => PostStatus::Published,
+        'status' => $status,
     ]);
 
     $postPlatform = PostPlatform::factory()->linkedin()->create([
@@ -220,7 +220,12 @@
             ],
         ])
         ->assertUnprocessable();
-});
+})->with([
+    PostStatus::Published,
+    PostStatus::PartiallyPublished,
+    PostStatus::Failed,
+    PostStatus::Publishing,
+]);
 
 it('validates post update fields', function () {
     $post = Post::factory()->create([

tests/Feature/Mcp/PostPublishToolTest.php

@@ -106,18 +106,23 @@
     $response->assertHasErrors(['Post not found.']);
 });
 
-test('update post rejects already-published post', function () {
+test('update post rejects posts in any terminal state', function (PostStatus $status) {
     $post = Post::factory()->create([
         'workspace_id' => $this->workspace->id,
         'user_id' => $this->user->id,
-        'status' => PostStatus::Published,
+        'status' => $status,
     ]);
 
     $response = TryPostServer::actingAs($this->user)
         ->tool(UpdatePostTool::class, ['post_id' => $post->id, 'content' => 'x']);
 
     $response->assertHasErrors(['Cannot edit a published post.']);
-});
+})->with([
+    PostStatus::Published,
+    PostStatus::PartiallyPublished,
+    PostStatus::Failed,
+    PostStatus::Publishing,
+]);
 
 test('update post rejects a platforms[].id that belongs to another post', function () {
     $myPost = Post::factory()->create([