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.

hermes_cli/profiles.py

@@ -1010,7 +1010,6 @@ def delete_profile(name: str, yes: bool = False) -> Path:
             print(f"✓ Removed {wrapper_path}")
 
     # 4. Remove profile directory
-    remove_error: Exception | None = None
     try:
         def _make_writable(func, path, exc):
             """onexc/onerror handler: add +w on PermissionError so rmtree can proceed.
@@ -1057,7 +1056,6 @@ def delete_profile(name: str, yes: bool = False) -> Path:
         print(f"✓ Removed {profile_dir}")
     except Exception as e:
         print(f"⚠ Could not remove {profile_dir}: {e}")
-        remove_error = e
 
     # 5. Clear active_profile if it pointed to this profile
     try:
@@ -1068,9 +1066,6 @@ def delete_profile(name: str, yes: bool = False) -> Path:
     except Exception:
         pass
 
-    if remove_error is not None:
-        raise RuntimeError(f"Could not remove profile directory {profile_dir}: {remove_error}") from remove_error
-
     print(f"\nProfile '{canon}' deleted.")
     return profile_dir