feat: add CountPostsOfSite query and DB method

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

providers/db/gen/sqlgen/posts.sql.go

@@ -9,6 +9,28 @@ import (
 	"context"
 )
 
+const countPostsOfSite = `-- name: CountPostsOfSite :one
+SELECT COUNT(*) FROM posts
+WHERE site_id = ?1 AND (
+    CASE CAST (?2 AS TEXT)
+        WHEN 'deleted' THEN deleted_at > 0
+        ELSE deleted_at = 0
+    END
+)
+`
+
+type CountPostsOfSiteParams struct {
+	SiteID     int64
+	PostFilter string
+}
+
+func (q *Queries) CountPostsOfSite(ctx context.Context, arg CountPostsOfSiteParams) (int64, error) {
+	row := q.db.QueryRowContext(ctx, countPostsOfSite, arg.SiteID, arg.PostFilter)
+	var count int64
+	err := row.Scan(&count)
+	return count, err
+}
+
 const hardDeletePost = `-- name: HardDeletePost :exec
 DELETE FROM posts WHERE id = ?
 `