fix: use conversation history to determine eyes reaction in Assistant View DMs

The previous check `not event.get("thread_ts")` never triggered in
Assistant View because thread_ts is always present. Instead, check
whether a conversation session/history already exists to decide if
this is the first message in the thread.

Author: mwbrooks

claude-agent-sdk/listeners/events/message_im.py

@@ -53,17 +53,17 @@ async def handle_message_im(
             ],
         )
 
-        # Add eyes reaction only to the first message (not threaded replies)
-        if not event.get("thread_ts"):
+        # Get session ID for conversation context
+        existing_session_id = session_store.get_session(channel_id, thread_ts)
+
+        # Add eyes reaction only to the first message in a thread
+        if not existing_session_id:
             await client.reactions_add(
                 channel=channel_id,
                 timestamp=event["ts"],
                 name="eyes",
             )
 
-        # Get session ID for conversation context
-        existing_session_id = session_store.get_session(channel_id, thread_ts)
-
         # Run the agent
         response_text, new_session_id = await run_casey_agent(
             text, session_id=existing_session_id

openai-agents-sdk/listeners/events/message_im.py

@@ -52,17 +52,17 @@ def handle_message_im(client: WebClient, event: dict, logger: Logger, say: Say):
             ],
         )
 
-        # Add eyes reaction only to the first message (not threaded replies)
-        if not event.get("thread_ts"):
+        # Get conversation history
+        history = conversation_store.get_history(channel_id, thread_ts)
+
+        # Add eyes reaction only to the first message in a thread
+        if history is None:
             client.reactions_add(
                 channel=channel_id,
                 timestamp=event["ts"],
                 name="eyes",
             )
 
-        # Get conversation history
-        history = conversation_store.get_history(channel_id, thread_ts)
-
         # Build input for the agent
         if history:
             input_items = history + [{"role": "user", "content": text}]

pydantic-ai/listeners/events/message_im.py

@@ -51,17 +51,17 @@ def handle_message_im(client: WebClient, event: dict, logger: Logger, say: Say):
             ],
         )
 
-        # Add eyes reaction only to the first message (not threaded replies)
-        if not event.get("thread_ts"):
+        # Get conversation history
+        history = conversation_store.get_history(channel_id, thread_ts)
+
+        # Add eyes reaction only to the first message in a thread
+        if history is None:
             client.reactions_add(
                 channel=channel_id,
                 timestamp=event["ts"],
                 name="eyes",
             )
 
-        # Get conversation history
-        history = conversation_store.get_history(channel_id, thread_ts)
-
         # Run the agent
         deps = CaseyDeps(
             client=client,