connect thumbnail selection signal to main controller; enhance thumbnail handling with media ID

core/database.py

@@ -125,6 +125,14 @@ class DatabaseManager:
         )
         self.conn.commit()
 
+    def get_media(self, media_id: int) -> dict | None:
+        if self.conn is None:
+            raise RuntimeError("Database not connected")
+        cur = self.conn.cursor()
+        cur.execute("SELECT * FROM media WHERE id = ?", (media_id,))
+        row = cur.fetchone()
+        return dict(row) if row else None
+
     def get_media_for_color(self, color_id: int) -> list[dict]:
         if self.conn is None:
             raise RuntimeError("Database not connected")