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.

web/package.json

@@ -7,8 +7,7 @@
     "dev": "vite",
     "build": "tsc -b && vite build",
     "lint": "eslint .",
-    "preview": "vite preview",
-    "typecheck": "tsc -p . --noEmit"
+    "preview": "vite preview"
   },
   "dependencies": {
     "@nous-research/ui": "0.18.2",
@@ -36,7 +35,7 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",
-    "@types/node": "^24.13.2",
+    "@types/node": "^24.12.0",
     "@types/qrcode": "^1.5.6",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
@@ -46,7 +45,7 @@
     "eslint-plugin-react-refresh": "^0.5.2",
     "globals": "^17.4.0",
     "three": "^0.180.0",
-    "typescript": "^6.0.3",
+    "typescript": "~5.9.3",
     "typescript-eslint": "^8.56.1",
     "vite": "^7.3.1"
   }