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.

apps/desktop/electron/workspace-cwd.test.cjs

@@ -1,45 +0,0 @@
-/**
- * Tests for electron/workspace-cwd.cjs.
- *
- * Run with: node --test electron/workspace-cwd.test.cjs
- */
-
-const test = require('node:test')
-const assert = require('node:assert/strict')
-const path = require('node:path')
-
-const { isPackagedInstallPath } = require('./workspace-cwd.cjs')
-
-const installRoot = path.resolve('/opt/Hermes')
-
-test('isPackagedInstallPath returns false when not packaged', () => {
-  assert.equal(
-    isPackagedInstallPath(installRoot, { isPackaged: false, installRoots: [installRoot] }),
-    false
-  )
-})
-
-test('isPackagedInstallPath flags the install root itself', () => {
-  assert.equal(
-    isPackagedInstallPath(installRoot, { isPackaged: true, installRoots: [installRoot] }),
-    true
-  )
-})
-
-test('isPackagedInstallPath flags paths nested under the install root', () => {
-  const nested = path.join(installRoot, 'resources', 'app.asar')
-
-  assert.equal(
-    isPackagedInstallPath(nested, { isPackaged: true, installRoots: [installRoot] }),
-    true
-  )
-})
-
-test('isPackagedInstallPath ignores paths outside the install root', () => {
-  const homeProject = path.resolve('/home/user/projects/demo')
-
-  assert.equal(
-    isPackagedInstallPath(homeProject, { isPackaged: true, installRoots: [installRoot] }),
-    false
-  )
-})