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.

tests/hermes_cli/test_cron.py

@@ -55,6 +55,7 @@ class TestCronCommandLifecycle:
                 repeat=None,
                 skill=None,
                 skills=["maps", "blogwatcher"],
+                profile="default",
                 clear_skills=False,
             )
         )
@@ -63,6 +64,7 @@ class TestCronCommandLifecycle:
         assert updated["name"] == "Edited Job"
         assert updated["prompt"] == "Revised prompt"
         assert updated["schedule_display"] == "every 120m"
+        assert updated["profile"] == "default"
 
         cron_command(
             Namespace(
@@ -75,12 +77,14 @@ class TestCronCommandLifecycle:
                 repeat=None,
                 skill=None,
                 skills=None,
+                profile="",
                 clear_skills=True,
             )
         )
         cleared = get_job(job["id"])
         assert cleared["skills"] == []
         assert cleared["skill"] is None
+        assert cleared["profile"] is None
 
         out = capsys.readouterr().out
         assert "Updated job" in out
@@ -96,6 +100,7 @@ class TestCronCommandLifecycle:
                 repeat=None,
                 skill=None,
                 skills=["blogwatcher", "maps"],
+                profile="default",
             )
         )
         out = capsys.readouterr().out
@@ -105,6 +110,7 @@ class TestCronCommandLifecycle:
         assert len(jobs) == 1
         assert jobs[0]["skills"] == ["blogwatcher", "maps"]
         assert jobs[0]["name"] == "Skill combo"
+        assert jobs[0]["profile"] == "default"
 
     def test_list_does_not_crash_when_repeat_is_null(self, tmp_cron_dir, capsys):
         """A one-shot job can be persisted with ``"repeat": null``. `cron