fix(gateway): follow compression continuations during /resume

gateway/run.py

@@ -7228,13 +7228,19 @@ class GatewayRunner:
                 logger.debug("Failed to list titled sessions: %s", e)
                 return f"Could not list sessions: {e}"
 
-        # Resolve the name to a session ID
+        # Resolve the name to a session ID.
         target_id = self._session_db.resolve_session_by_title(name)
         if not target_id:
             return (
                 f"No session found matching '**{name}**'.\n"
                 "Use `/resume` with no arguments to see available sessions."
             )
+        # Compression creates child continuations that hold the live transcript.
+        # Follow that chain so gateway /resume matches CLI behavior (#15000).
+        try:
+            target_id = self._session_db.resolve_resume_session_id(target_id)
+        except Exception as e:
+            logger.debug("Failed to resolve resume continuation for %s: %s", target_id, e)
 
         # Check if already on that session
         current_entry = self.session_store.get_or_create_session(source)

tests/gateway/test_resume_command.py

@@ -179,6 +179,40 @@ class TestHandleResumeCommand:
         assert call_args[0][1] == "sess_v2"
         db.close()
 
+    @pytest.mark.asyncio
+    async def test_resume_follows_compression_continuation(self, tmp_path):
+        """Gateway /resume should reopen the live descendant after compression."""
+        from hermes_state import SessionDB
+
+        db = SessionDB(db_path=tmp_path / "state.db")
+        db.create_session("compressed_root", "telegram")
+        db.set_session_title("compressed_root", "Compressed Work")
+        db.end_session("compressed_root", "compression")
+        db.create_session("compressed_child", "telegram", parent_session_id="compressed_root")
+        db.append_message("compressed_child", "user", "hello from continuation")
+        db.create_session("current_session_001", "telegram")
+
+        event = _make_event(text="/resume Compressed Work")
+        runner = _make_runner(
+            session_db=db,
+            current_session_id="current_session_001",
+            event=event,
+        )
+        runner.session_store.load_transcript.side_effect = (
+            lambda session_id: [{"role": "user", "content": "hello from continuation"}]
+            if session_id == "compressed_child"
+            else []
+        )
+
+        result = await runner._handle_resume_command(event)
+
+        assert "Resumed session" in result
+        assert "(1 message)" in result
+        call_args = runner.session_store.switch_session.call_args
+        assert call_args[0][1] == "compressed_child"
+        runner.session_store.load_transcript.assert_called_with("compressed_child")
+        db.close()
+
     @pytest.mark.asyncio
     async def test_resume_clears_running_agent(self, tmp_path):
         """Switching sessions clears any cached running agent."""