feat(harvester,jobs): fast gateway harvesting, parallel thread polling, dynamic sidechat spawning

- Implement muse_hybrid fast gateway in response-harvester.py with ThreadPoolExecutor
- Reduce harvest cycle time from ~1m50s to ~18s; eliminate browser tab-hopping and CDP lock contention
- Add smart active thread filtering in get_monitored_threads to prune dead historical test pipes
- Fix initial watermark ingestion logic so fresh sidechats process first-arrival job responses
- Configure gw_wait window in dm.py (20s on reply:expected) so backend generation is not prematurely severed
- Update box-http-health, box-service-health, box-deep-health to dynamic timestamped sidechats without reuse_key
- Fix heartbeat job to route to dedicated heartbeat channel

bin/dm.py

@@ -578,7 +578,8 @@ def dm_send(agent, target, message, verify=True, raw=False,
     if is_uuid and recipient in VALID_AGENTS:
         try:
             import muse_hybrid
-            gw_res, gw_err = muse_hybrid.send_message(recipient, tagged, thread_id=nav_target, wait=0)
+            gw_wait = 20 if tags.get("reply:expected") else 10
+            gw_res, gw_err = muse_hybrid.send_message(recipient, tagged, thread_id=nav_target, wait=gw_wait)
             if gw_res and not gw_err:
                 thread_uuid = nav_target
                 tags["thread"] = thread_uuid
@@ -635,7 +636,8 @@ def dm_send(agent, target, message, verify=True, raw=False,
                 os.replace(tmp_sc, SIDCHAT_MAP_FILE)
 
                 # Send immediately via gateway
-                gw_res, gw_err = muse_hybrid.send_message(recipient, tagged, thread_id=matched_uuid, wait=0)
+                gw_wait = 20 if tags.get("reply:expected") else 10
+                gw_res, gw_err = muse_hybrid.send_message(recipient, tagged, thread_id=matched_uuid, wait=gw_wait)
                 if gw_res and not gw_err:
                     thread_uuid = matched_uuid
                     tags["thread"] = thread_uuid