Add an image field, required for WordPress posts

Posts get a nullable image_url. WordPressPublisher now downloads it
and uploads it to WordPress's media endpoint before creating the
post, setting it as featured_media — and rejects publishing (without
touching status) if a blog post has no image set, mirroring the
existing title requirement. Every other network treats it as optional.

Not enforced at save time, same as title — you can still draft an
incomplete WordPress post, it just can't be published until an image
is set. Exposed through the UI form (with a thumbnail/""missing""
indicator in the table), the JSON API, and the Python CLI wrapper.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/Support/Publishing/WordPressPublisher.php

@@ -3,6 +3,7 @@
 namespace App\Support\Publishing;
 
 use App\Models\Post;
+use App\Models\Site;
 use Illuminate\Http\Client\ConnectionException;
 use Illuminate\Support\Facades\Http;
 
@@ -19,6 +20,10 @@ class WordPressPublisher implements Publisher
             return PublishResult::rejected("Post {$post->id} has no title, required to publish to WordPress.");
         }
 
+        if (! $post->image_url) {
+            return PublishResult::rejected("Post {$post->id} has no image, required to publish to WordPress.");
+        }
+
         $site = $post->site;
 
         if ($site->cms_type !== 'wordpress') {
@@ -29,12 +34,19 @@ class WordPressPublisher implements Publisher
             return PublishResult::rejected("Site '{$site->name}' is missing WordPress credentials.");
         }
 
+        $mediaId = $this->uploadFeaturedImage($post, $site);
+
+        if ($mediaId instanceof PublishResult) {
+            return $mediaId;
+        }
+
         try {
             $response = Http::withBasicAuth($site->wp_username, $site->wp_app_password)
                 ->post(rtrim($site->url, '/').'/wp-json/wp/v2/posts', [
                     'title' => $post->title,
                     'content' => $post->body,
                     'status' => 'publish',
+                    'featured_media' => $mediaId,
                 ]);
         } catch (ConnectionException $e) {
             return PublishResult::failed("could not connect to site: {$e->getMessage()}");
@@ -52,4 +64,41 @@ class WordPressPublisher implements Publisher
 
         return PublishResult::success($link);
     }
+
+    private function uploadFeaturedImage(Post $post, Site $site): int|PublishResult
+    {
+        try {
+            $image = Http::get($post->image_url);
+        } catch (ConnectionException $e) {
+            return PublishResult::failed("could not download image: {$e->getMessage()}");
+        }
+
+        if ($image->failed()) {
+            return PublishResult::failed('could not download image: unexpected response from image URL');
+        }
+
+        $filename = basename(parse_url($post->image_url, PHP_URL_PATH) ?: '') ?: 'image.jpg';
+        $contentType = $image->header('Content-Type') ?: 'application/octet-stream';
+
+        try {
+            $response = Http::withBasicAuth($site->wp_username, $site->wp_app_password)
+                ->withBody($image->body(), $contentType)
+                ->withHeaders(['Content-Disposition' => "attachment; filename=\"{$filename}\""])
+                ->post(rtrim($site->url, '/').'/wp-json/wp/v2/media');
+        } catch (ConnectionException $e) {
+            return PublishResult::failed("could not connect to site: {$e->getMessage()}");
+        }
+
+        if ($response->failed()) {
+            return PublishResult::failed($response->json('message') ?? 'unexpected response from WordPress while uploading the image');
+        }
+
+        $mediaId = $response->json('id');
+
+        if (! $mediaId) {
+            return PublishResult::failed('unexpected response from WordPress: missing media id');
+        }
+
+        return $mediaId;
+    }
 }