story-kit: create 131_bug_get_agent_output_stream_always_times_out_for_running_agents

.story_kit/work/1_upcoming/131_bug_get_agent_output_stream_always_times_out_for_running_agents.md

@@ -25,6 +25,21 @@ The `get_agent_output` MCP tool consistently returns "Stream timed out; call aga
 
 `get_agent_output` streams back text tokens and status events from the running agent in real time. `session_id` is populated once the agent's first streaming event arrives.
 
+## Reopened — Previous Fix Did Not Work
+
+This was archived after a coder pass but the bug is still present. With 3 agents actively running:
+- `get_agent_output` returned 141 events on one call, then 0 events on the next call with a 5s timeout
+- None of the events contained text output — only metadata/status events
+- The server logs (`get_server_logs`) DO show agent activity (spawn commands, MCP calls), so the agents are working — the output just isn't being captured/forwarded
+
+### Investigation needed
+
+The coder needs to trace the full data path:
+1. How does `run_agent_pty_streaming` (server/src/agents.rs) capture PTY output from the claude process?
+2. How are those events published to the broadcast channel that `get_agent_output` subscribes to?
+3. Is the broadcast channel being created before the agent starts producing output, or is there a race where early events are lost?
+4. Are text tokens from the PTY being sent as `AgentEvent` variants that `get_agent_output` actually serializes, or are they filtered out?
+
 ## Acceptance Criteria
 
 - [ ] get_agent_output returns streaming text events while an agent is actively running