opentui(phase3): launcher integration — HERMES_TUI_ENGINE dual-engine

hermes --tui launches the native OpenTUI engine (Bun) when
HERMES_TUI_ENGINE=opentui (env) or display.tui_engine=opentui (config);
Ink stays the default and the shipping path is untouched.

- _resolve_tui_engine() (env > config > ink); refuses opentui on
  Windows/Termux (no Bun) -> falls back to ink with a notice.
- _make_opentui_argv() -> [bun, src/entry.real.tsx] (no build step).
- _bun_bin() with HERMES_BUN override.
- Branch at top of _make_tui_argv BEFORE _ensure_tui_node (Bun-only host
  must not bootstrap Node).
- Gate _launch_tui NODE_OPTIONS/--max-old-space-size on engine==ink (Bun
  is JSC; the V8 flag errors/ignores).

Verified end-to-end via tmux: real hermes --tui -> Bun -> OpenTUI ->
real Python gateway streamed a real reply. No-flag default still ink.

agent/display.py

@@ -858,20 +858,6 @@ def _detect_tool_failure(tool_name: str, result: str | None) -> tuple[bool, str]
     return False, ""
 
 
-def _used_free_parallel(result: str | None) -> bool:
-    """True when a web result came from Parallel's free Search MCP.
-
-    Only the keyless Parallel path tags its result with ``provider="parallel"``;
-    the paid REST path and every other provider omit it. Used to label the tool
-    line "Parallel search" / "Parallel fetch" exactly when the free MCP served
-    the call.
-    """
-    if not isinstance(result, str) or '"provider"' not in result:
-        return False
-    data = safe_json_loads(result)
-    return isinstance(data, dict) and str(data.get("provider", "")).lower() == "parallel"
-
-
 def get_cute_tool_message(
     tool_name: str, args: dict, duration: float, result: str | None = None,
 ) -> str:
@@ -909,17 +895,15 @@ def get_cute_tool_message(
         return f"{line}{failure_suffix}"
 
     if tool_name == "web_search":
-        verb = "Parallel search" if _used_free_parallel(result) else "search"
-        return _wrap(f"┊ 🔍 {verb:<9} {_trunc(args.get('query', ''), 42)}  {dur}")
+        return _wrap(f"┊ 🔍 search    {_trunc(args.get('query', ''), 42)}  {dur}")
     if tool_name == "web_extract":
-        verb = "Parallel fetch" if _used_free_parallel(result) else "fetch"
         urls = args.get("urls", [])
         if urls:
             url = urls[0] if isinstance(urls, list) else str(urls)
             domain = url.replace("https://", "").replace("http://", "").split("/")[0]
             extra = f" +{len(urls)-1}" if len(urls) > 1 else ""
-            return _wrap(f"┊ 📄 {verb:<9} {_trunc(domain, 35)}{extra}  {dur}")
-        return _wrap(f"┊ 📄 {verb:<9} pages  {dur}")
+            return _wrap(f"┊ 📄 fetch     {_trunc(domain, 35)}{extra}  {dur}")
+        return _wrap(f"┊ 📄 fetch     pages  {dur}")
     if tool_name == "terminal":
         return _wrap(f"┊ 💻 $         {_trunc(args.get('command', ''), 42)}  {dur}")
     if tool_name == "process":