Adding feature to remove annotations

src/database/db_manager.py

@@ -706,6 +706,25 @@ class DatabaseManager:
         finally:
             conn.close()
 
+    def delete_annotation(self, annotation_id: int) -> bool:
+        """
+        Delete a manual annotation by ID.
+
+        Args:
+            annotation_id: ID of the annotation to delete
+
+        Returns:
+            True if an annotation was deleted, False otherwise.
+        """
+        conn = self.get_connection()
+        try:
+            cursor = conn.cursor()
+            cursor.execute("DELETE FROM annotations WHERE id = ?", (annotation_id,))
+            conn.commit()
+            return cursor.rowcount > 0
+        finally:
+            conn.close()
+
     # ==================== Object Class Operations ====================
 
     def get_object_classes(self) -> List[Dict]: