feat: add plugin runtime and cross-device task orchestration

artemis/data_engine/storage.py

@@ -134,6 +134,14 @@ class StorageManager:
                 )
             """)
 
+            conn.execute("""
+                CREATE TABLE IF NOT EXISTS plugin_image_references (
+                    session_id TEXT NOT NULL,
+                    image_name TEXT NOT NULL,
+                    PRIMARY KEY (session_id, image_name)
+                )
+            """)
+
             conn.execute("""
                 CREATE TABLE IF NOT EXISTS steps (
                     step_id TEXT PRIMARY KEY,
@@ -1102,6 +1110,7 @@ class StorageManager:
         with self._get_connection() as conn:
             conn.execute("PRAGMA foreign_keys = OFF")
             tables = [
+                "plugin_image_references",
                 "video_analysis_observations",
                 "video_analysis_segments",
                 "failed_outputs",
@@ -1154,6 +1163,15 @@ class StorageManager:
         except ValueError:
             return False
 
+    def reference_plugin_image(self, session_id: UUID | str, image_name: str):
+        """Keep tool-only images alive until their last owning task is deleted."""
+        with self._get_connection() as conn:
+            conn.execute(
+                "INSERT OR IGNORE INTO plugin_image_references VALUES (?, ?)",
+                (str(session_id), image_name),
+            )
+            conn.commit()
+
     def delete_session(self, session_id: UUID):
         """Delete all data associated with a session, including files on disk."""
         session_id_str = str(session_id)
@@ -1173,6 +1191,13 @@ class StorageManager:
                     for name in row
                     if name
                 }
+                image_names.update(
+                    row[0]
+                    for row in conn.execute(
+                        "SELECT image_name FROM plugin_image_references WHERE session_id=?",
+                        (session_id_str,),
+                    )
+                )
                 cursor = conn.execute(
                     "SELECT video_id, local_video_path FROM video_recordings WHERE session_id = ?",
                     (session_id_str,),
@@ -1205,6 +1230,7 @@ class StorageManager:
                 except sqlite3.OperationalError as e:
                     logger.warning(f"Failed to delete video memory from {table}: {e}")
             tables = [
+                "plugin_image_references",
                 "failed_outputs",
                 "traces",
                 "background_tasks",
@@ -1223,8 +1249,9 @@ class StorageManager:
                     raise
             for name in image_names:
                 if not conn.execute(
-                    "SELECT 1 FROM steps WHERE pre_image_name=? OR post_image_name=? LIMIT 1",
-                    (name, name),
+                    "SELECT 1 FROM steps WHERE pre_image_name=? OR post_image_name=? "
+                    "UNION ALL SELECT 1 FROM plugin_image_references WHERE image_name=? LIMIT 1",
+                    (name, name, name),
                 ).fetchone():
                     conn.execute("DELETE FROM images WHERE image_name=?", (name,))
                     orphaned_images.append(name)