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.

gateway/session.py

@@ -91,7 +91,6 @@ class SessionSource:
     guild_id: Optional[str] = None  # Discord guild / Slack workspace / Matrix server scope
     parent_chat_id: Optional[str] = None  # Parent channel when chat_id refers to a thread
     message_id: Optional[str] = None  # ID of the triggering message (for pin/reply/react)
-    role_authorized: bool = False  # True when adapter granted access via role (not user ID)
     
     @property
     def description(self) -> str:
@@ -294,22 +293,6 @@ def build_session_context_prompt(
     if context.source.chat_topic:
         lines.append(f"**Channel Topic:** {context.source.chat_topic}")
 
-    if context.source.platform == Platform.MATRIX:
-        src = context.source
-        room_name = src.chat_name or src.chat_id
-        room_id = _hash_chat_id(src.chat_id) if redact_pii else src.chat_id
-        lines.append("")
-        lines.append(f"**Matrix Room:** {room_name}")
-        lines.append(f"**Matrix Room ID:** {room_id}")
-        if src.thread_id:
-            thread_id = _hash_chat_id(src.thread_id) if redact_pii else src.thread_id
-            lines.append(f"**Matrix Thread:** {thread_id}")
-        lines.append(
-            "**Matrix room boundary:** Treat this turn as scoped to the current "
-            "Matrix room/thread only. Do not assume unresolved references are "
-            "about other Matrix rooms or projects unless the user explicitly says so."
-        )
-
     # User identity.
     # In shared multi-user sessions (shared threads OR shared non-thread groups
     # when group_sessions_per_user=False), multiple users contribute to the same
@@ -1280,17 +1263,6 @@ class SessionStore:
         entries.sort(key=lambda e: e.updated_at, reverse=True)
 
         return entries
-
-    def lookup_by_session_id(self, session_id: str) -> Optional[SessionEntry]:
-        """Return the active session entry for a persisted session ID, if any."""
-        if not session_id:
-            return None
-        with self._lock:
-            self._ensure_loaded_locked()
-            for entry in self._entries.values():
-                if entry.session_id == session_id:
-                    return entry
-        return None
     
     def append_to_transcript(self, session_id: str, message: Dict[str, Any], skip_db: bool = False) -> None:
         """Append a message to a session's transcript (SQLite).