feat: support uploaded images in debug voice preview

Allow paste/drag temporary image assets so vision turns work without a live camera frame.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/services/conversation_history.py

@@ -176,6 +176,8 @@ class ConversationRecorder:
         *,
         input_id: str,
         timestamp: object,
+        content: str = "",
+        source: str = "camera_capture",
         mime_type: str = "image/jpeg",
     ) -> None:
         """Persist a captured frame without delaying the realtime model turn."""
@@ -185,6 +187,8 @@ class ConversationRecorder:
                 data,
                 input_id=input_id,
                 timestamp=timestamp,
+                content=content,
+                source=source,
                 mime_type=mime_type,
             ),
             name=f"conversation-image:{self.session_id}:{input_id}",
@@ -198,6 +202,8 @@ class ConversationRecorder:
         *,
         input_id: str,
         timestamp: object,
+        content: str,
+        source: str,
         mime_type: str,
     ) -> None:
         message_id = f"msg_{uuid4().hex[:20]}"
@@ -221,11 +227,11 @@ class ConversationRecorder:
                             sequence=next_sequence,
                             role="user",
                             content_type="image",
-                            content="",
+                            content=content.strip(),
                             occurred_at=_parse_timestamp(timestamp),
                             extra={
                                 "input_id": input_id,
-                                "source": "camera_capture",
+                                "source": source,
                             },
                         )
                     )
@@ -238,7 +244,7 @@ class ConversationRecorder:
                             storage_uri=storage_uri(key),
                             mime_type=mime_type,
                             size_bytes=len(data),
-                            extra={"input_id": input_id},
+                            extra={"input_id": input_id, "source": source},
                         )
                     )
                     conversation = await db.get(ConversationSession, self.session_id)