feat(blog): add SEO fields, scheduling, and representative ownership to blog posts

- Introduced new SEO fields (meta_title, meta_description, primary_keyword, secondary_keywords, faq, internal_links, external_links, reading_time, canonical_url, og_image) to the Blog entity.
- Added scheduling capability with a scheduled_at field to manage automatic publishing of blog posts.
- Implemented representative ownership through a foreign key representation_id in the Blog entity, allowing representatives to manage their own posts.
- Updated BlogController and RepresentationBlogController to handle new fields and ensure proper data handling for SEO and scheduling.
- Created BlogWriter service to encapsulate the logic for applying SEO and scheduling fields to blog entities.
- Added PublishScheduledBlogsMessage and its handler to manage the publishing of scheduled blogs.
- Implemented ScheduledBlogPublisher service to publish drafts whose scheduled_at has arrived, respecting review status.
- Created migration to update the database schema with new fields and constraints.
- Added tests to ensure the correct functionality of new features, including SEO fields, representative scope, and scheduled publishing.

src/Blog/Service/BlogWriter.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace App\Blog\Service;
+
+use App\Blog\Entity\Blog;
+
+/**
+ * Maps the SEO + scheduling fields of a blog write request onto the entity.
+ * Shared by the admin BlogController and the representative RepresentationBlogController
+ * so both accept the same field set without duplicating the mapping.
+ *
+ * Core fields (title/body/summary/tags/status/image/city) and ownership stay in
+ * the controllers — this service is only the optional SEO/scheduling surface.
+ */
+class BlogWriter
+{
+    /** Apply any SEO / scheduling fields present in $data. Missing keys are left untouched. */
+    public function applySeoFields(Blog $blog, array $data): void
+    {
+        if (array_key_exists('meta_title', $data))       $blog->setMetaTitle($this->str($data['meta_title']));
+        if (array_key_exists('meta_description', $data))  $blog->setMetaDescription($this->str($data['meta_description']));
+        if (array_key_exists('primary_keyword', $data))   $blog->setPrimaryKeyword($this->str($data['primary_keyword']));
+        if (array_key_exists('secondary_keywords', $data)) $blog->setSecondaryKeywords($this->arr($data['secondary_keywords']));
+        if (array_key_exists('faq', $data))               $blog->setFaq($this->faq($data['faq']));
+        if (array_key_exists('internal_links', $data))    $blog->setInternalLinks($this->arr($data['internal_links']));
+        if (array_key_exists('external_links', $data))    $blog->setExternalLinks($this->arr($data['external_links']));
+        if (array_key_exists('reading_time', $data))      $blog->setReadingTime($this->int($data['reading_time']));
+        if (array_key_exists('canonical_url', $data))     $blog->setCanonicalUrl($this->str($data['canonical_url']));
+        if (array_key_exists('og_image', $data))          $blog->setOgImage($this->str($data['og_image']));
+        if (array_key_exists('scheduled_at', $data))      $blog->setScheduledAt($this->int($data['scheduled_at']));
+    }
+
+    private function str(mixed $v): ?string
+    {
+        $v = is_string($v) ? trim($v) : $v;
+        return ($v === null || $v === '') ? null : (string) $v;
+    }
+
+    private function int(mixed $v): ?int
+    {
+        return ($v === null || $v === '') ? null : (int) $v;
+    }
+
+    /** @return list<string> non-empty string values */
+    private function arr(mixed $v): array
+    {
+        if (!is_array($v)) {
+            return [];
+        }
+        return array_values(array_filter(array_map(
+            fn($x) => is_string($x) ? trim($x) : $x,
+            $v
+        ), fn($x) => $x !== null && $x !== ''));
+    }
+
+    /** @return list<array{q:string,a:string}> — drops malformed entries. */
+    private function faq(mixed $v): array
+    {
+        if (!is_array($v)) {
+            return [];
+        }
+        $out = [];
+        foreach ($v as $item) {
+            if (is_array($item) && !empty($item['q']) && !empty($item['a'])) {
+                $out[] = ['q' => trim((string) $item['q']), 'a' => trim((string) $item['a'])];
+            }
+        }
+        return $out;
+    }
+}

src/Blog/Service/ScheduledBlogPublisher.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Blog\Service;
+
+use App\Blog\Entity\Blog;
+use App\Blog\Repository\BlogRepository;
+
+/**
+ * Publishes drafts whose scheduled_at has arrived. A post in the review workflow
+ * is published only once review_status = approved — the medical-review gate wins
+ * over the schedule, so AI-generated content is never auto-published unreviewed.
+ */
+class ScheduledBlogPublisher
+{
+    public function __construct(private readonly BlogRepository $blogRepo) {}
+
+    /** @return int number of posts published */
+    public function publishDue(?int $now = null): int
+    {
+        $now = $now ?? time();
+        $due = $this->blogRepo->findDueForPublish($now);
+        foreach ($due as $blog) {
+            $blog->setStatus(Blog::STATUS_PUBLISHED);
+            $this->blogRepo->save($blog);
+        }
+        return count($due);
+    }
+}