feat: add pty monitoring for claude code

src/beaver_gateway/backends/claude_code.py

@@ -226,6 +226,18 @@ class ClaudeCodeBackendAdapter:
     def live_session_count(self) -> int:
         return self._backend.live_session_count
 
+    @property
+    def live_sessions(self) -> dict[str, Any]:
+        """Live PTY processes keyed by claude session_id.
+
+        Pass-through to the underlying ``ClaudeCodeBackend``. The value
+        type is the claude-code-api ``PtyClaudeProcess``; admin code
+        consumes ``captured_output()`` / ``add_output_listener`` /
+        ``write`` from it. Typed as ``Any`` to avoid leaking the lower
+        layer's type into the gateway's public surface.
+        """
+        return self._backend.live_sessions
+
     async def __aenter__(self) -> Self:
         await self._backend.__aenter__()
         return self