fix(config): read browser inactivity timeout from config

tools/browser_tool.py

@@ -1177,10 +1177,23 @@ _cleanup_done = False
 # Inactivity Timeout Configuration
 # =============================================================================
 
-# Session inactivity timeout (seconds) - cleanup if no activity for this long
-# Default: 5 minutes. Needs headroom for LLM reasoning between browser commands,
-# especially when subagents are doing multi-step browser tasks.
-BROWSER_SESSION_INACTIVITY_TIMEOUT = env_int("BROWSER_INACTIVITY_TIMEOUT", 300)
+# Session inactivity timeout (seconds) - cleanup if no activity for this long.
+# config.yaml is authoritative; BROWSER_INACTIVITY_TIMEOUT remains a legacy
+# fallback so old deployments keep working if they have not migrated yet.
+def _get_session_inactivity_timeout() -> int:
+    result = env_int("BROWSER_INACTIVITY_TIMEOUT", 300)
+    try:
+        from hermes_cli.config import read_raw_config
+        cfg = read_raw_config()
+        val = cfg_get(cfg, "browser", "inactivity_timeout")
+        if val is not None:
+            result = max(int(val), 30)  # Floor at 30s to avoid instant reaping
+    except Exception as e:
+        logger.debug("Could not read inactivity_timeout from config: %s", e)
+    return result
+
+
+BROWSER_SESSION_INACTIVITY_TIMEOUT = _get_session_inactivity_timeout()
 
 # Track last activity time per session
 _session_last_activity: Dict[str, float] = {}