perf(cli): skip launcher-side plugin discovery for TUI handoff

(cherry picked from commit e2e0edd6b8ec10d02e867ff11dd1f9b4961a1ba7)

hermes_cli/main.py

@@ -11166,22 +11166,25 @@ def _prepare_agent_startup(args) -> None:
         return
 
     _accept_hooks = bool(getattr(args, "accept_hooks", False))
-    try:
-        from hermes_cli.plugins import start_background_plugin_discovery
+    if not _is_tui_chat_launch(args):
+        # The TUI backend process does its own plugin discovery; the launcher
+        # only spawns Node, so discovery here would be thrown-away work.
+        try:
+            from hermes_cli.plugins import start_background_plugin_discovery
 
-        # Discovery runs in a daemon thread so its ~150ms of manifest
-        # scanning + plugin imports overlaps the rest of startup (cli /
-        # prompt_toolkit imports, worktree git calls). Correctness is
-        # unchanged: every synchronous reader goes through
-        # discover_plugins(), which joins this thread first — including
-        # the discover_plugins() call model_tools makes at import time,
-        # which happens before any tool list is built.
-        start_background_plugin_discovery()
-    except Exception:
-        logger.warning(
-            "plugin discovery failed at CLI startup",
-            exc_info=True,
-        )
+            # Discovery runs in a daemon thread so its ~150ms of manifest
+            # scanning + plugin imports overlaps the rest of startup (cli /
+            # prompt_toolkit imports, worktree git calls). Correctness is
+            # unchanged: every synchronous reader goes through
+            # discover_plugins(), which joins this thread first — including
+            # the discover_plugins() call model_tools makes at import time,
+            # which happens before any tool list is built.
+            start_background_plugin_discovery()
+        except Exception:
+            logger.warning(
+                "plugin discovery failed at CLI startup",
+                exc_info=True,
+            )
     _run_inline_mcp_discovery = True
     if _is_tui_chat_launch(args):
         # The TUI launcher hands off to a dedicated startup path that already

tests/hermes_cli/test_tui_launcher_skips_plugin_discovery.py

@@ -0,0 +1,63 @@
+
+"""Regression test: the TUI launcher must not spend time on plugin discovery.
+
+`hermes --tui` just spawns a Node process; the spawned tui_gateway backend
+performs its own plugin discovery. Running discover_plugins() in the
+launcher added ~0.5s to every `hermes --tui` startup for work the backend
+then redoes. Plain chat must still discover plugins.
+"""
+
+from __future__ import annotations
+
+from argparse import Namespace
+import sys
+import types
+
+from hermes_cli import main as main_mod
+
+
+def _install_discover_spy(monkeypatch):
+    calls = []
+
+    def _discover():
+        calls.append("discover")
+
+    monkeypatch.setitem(
+        sys.modules,
+        "hermes_cli.plugins",
+        types.SimpleNamespace(
+            discover_plugins=_discover,
+            # main.py now kicks discovery off in a background thread; both
+            # entry points count as "discovery work happened in the launcher".
+            start_background_plugin_discovery=_discover,
+        ),
+    )
+    return calls
+
+
+def _args(**overrides):
+    base = {
+        "accept_hooks": False,
+        "yolo": False,
+        "safe_mode": False,
+        "command": None,
+        "query": None,
+        "image": None,
+    }
+    base.update(overrides)
+    return Namespace(**base)
+
+
+def test_plugin_discovery_skipped_for_tui_launch(monkeypatch):
+    calls = _install_discover_spy(monkeypatch)
+    main_mod._prepare_agent_startup(_args(tui=True))
+    assert calls == [], (
+        "Plugin discovery must not run in the TUI launcher: the spawned "
+        "tui_gateway backend discovers plugins itself."
+    )
+
+
+def test_plugin_discovery_runs_for_plain_chat(monkeypatch):
+    calls = _install_discover_spy(monkeypatch)
+    main_mod._prepare_agent_startup(_args(tui=False, command="chat"))
+    assert calls == ["discover"]