feat: add tag filtering to blog posts and implement JSON_CONTAINS DQL function

src/Blog/Repository/BlogRepository.php

@@ -14,24 +14,40 @@ class BlogRepository extends ServiceEntityRepository
     public function findBySlug(string $slug): ?Blog { return $this->findOneBy(['slug' => $slug]); }
 
     /** @return Blog[] published, newest first */
-    public function findPublished(int $page = 1, int $limit = 20): array
+    public function findPublished(int $page = 1, int $limit = 20, ?string $tag = null): array
     {
-        return $this->createQueryBuilder('b')
+        $qb = $this->createQueryBuilder('b')
             ->where('b.status = :status')
             ->setParameter('status', Blog::STATUS_PUBLISHED)
             ->orderBy('b.createdAt', 'DESC')
             ->setFirstResult(($page - 1) * $limit)
-            ->setMaxResults($limit)
-            ->getQuery()->getResult();
+            ->setMaxResults($limit);
+
+        $this->applyTagFilter($qb, $tag);
+
+        return $qb->getQuery()->getResult();
     }
 
-    public function countPublished(): int
+    public function countPublished(?string $tag = null): int
     {
-        return (int) $this->createQueryBuilder('b')
+        $qb = $this->createQueryBuilder('b')
             ->select('COUNT(b.id)')
             ->where('b.status = :status')
-            ->setParameter('status', Blog::STATUS_PUBLISHED)
-            ->getQuery()->getSingleScalarResult();
+            ->setParameter('status', Blog::STATUS_PUBLISHED);
+
+        $this->applyTagFilter($qb, $tag);
+
+        return (int) $qb->getQuery()->getSingleScalarResult();
+    }
+
+    private function applyTagFilter(\Doctrine\ORM\QueryBuilder $qb, ?string $tag): void
+    {
+        if ($tag === null || $tag === '') {
+            return;
+        }
+        // Blog.tags is a JSON array of tag names; match exact name membership.
+        $qb->andWhere('JSON_CONTAINS(b.tags, :tag) = 1')
+           ->setParameter('tag', json_encode($tag, JSON_UNESCAPED_UNICODE));
     }
 
     public function save(Blog $e, bool $flush = true): void { $this->getEntityManager()->persist($e); if ($flush) $this->getEntityManager()->flush(); }