fix(honcho): isolate session routing for multi-user gateway (#1500)

Salvaged from PR #1470 by adavyas.

Core fix: Honcho tool calls in a multi-session gateway could route to
the wrong session because honcho_tools.py relied on process-global
state. Now threads session context through the call chain:
  AIAgent._invoke_tool() → handle_function_call() → registry.dispatch()
  → handler **kw → _resolve_session_context()

Changes:
- Add _resolve_session_context() to prefer per-call context over globals
- Plumb honcho_manager + honcho_session_key through handle_function_call
- Add sync_honcho=False to run_conversation() for synthetic flush turns
- Pass honcho_session_key through gateway memory flush lifecycle
- Harden gateway PID detection when /proc cmdline is unreadable
- Make interrupt test scripts import-safe for pytest-xdist
- Wrap BibTeX examples in Jekyll raw blocks for docs build
- Fix thread-order-dependent assertion in client lifecycle test
- Expand Honcho docs: session isolation, lifecycle, routing internals

Dropped from original PR:
- Indentation change in _create_request_openai_client that would move
  client creation inside the lock (causes unnecessary contention)

Co-authored-by: adavyas <adavyas@users.noreply.github.com>

tests/gateway/test_honcho_lifecycle.py

@@ -90,6 +90,7 @@ class TestGatewayHonchoLifecycle:
         runner = _make_runner()
         event = _make_event()
         runner._shutdown_gateway_honcho = MagicMock()
+        runner._async_flush_memories = AsyncMock()
         runner.session_store = MagicMock()
         runner.session_store._generate_session_key.return_value = "gateway-key"
         runner.session_store._entries = {
@@ -100,4 +101,31 @@ class TestGatewayHonchoLifecycle:
         result = await runner._handle_reset_command(event)
 
         runner._shutdown_gateway_honcho.assert_called_once_with("gateway-key")
+        runner._async_flush_memories.assert_called_once_with("old-session", "gateway-key")
         assert "Session reset" in result
+
+    def test_flush_memories_reuses_gateway_session_key_and_skips_honcho_sync(self):
+        runner = _make_runner()
+        runner.session_store = MagicMock()
+        runner.session_store.load_transcript.return_value = [
+            {"role": "user", "content": "a"},
+            {"role": "assistant", "content": "b"},
+            {"role": "user", "content": "c"},
+            {"role": "assistant", "content": "d"},
+        ]
+        tmp_agent = MagicMock()
+
+        with (
+            patch("gateway.run._resolve_runtime_agent_kwargs", return_value={"api_key": "test-key"}),
+            patch("gateway.run._resolve_gateway_model", return_value="model-name"),
+            patch("run_agent.AIAgent", return_value=tmp_agent) as mock_agent_cls,
+        ):
+            runner._flush_memories_for_session("old-session", "gateway-key")
+
+        mock_agent_cls.assert_called_once()
+        _, kwargs = mock_agent_cls.call_args
+        assert kwargs["session_id"] == "old-session"
+        assert kwargs["honcho_session_key"] == "gateway-key"
+        tmp_agent.run_conversation.assert_called_once()
+        _, run_kwargs = tmp_agent.run_conversation.call_args
+        assert run_kwargs["sync_honcho"] is False

tests/gateway/test_resume_command.py

@@ -199,3 +199,28 @@ class TestHandleResumeCommand:
 
         assert real_key not in runner._running_agents
         db.close()
+
+    @pytest.mark.asyncio
+    async def test_resume_flushes_memories_with_gateway_session_key(self, tmp_path):
+        """Resume should preserve the gateway session key for Honcho flushes."""
+        from hermes_state import SessionDB
+
+        db = SessionDB(db_path=tmp_path / "state.db")
+        db.create_session("old_session", "telegram")
+        db.set_session_title("old_session", "Old Work")
+        db.create_session("current_session_001", "telegram")
+
+        event = _make_event(text="/resume Old Work")
+        runner = _make_runner(
+            session_db=db,
+            current_session_id="current_session_001",
+            event=event,
+        )
+
+        await runner._handle_resume_command(event)
+
+        runner._async_flush_memories.assert_called_once_with(
+            "current_session_001",
+            _session_key_for_event(event),
+        )
+        db.close()

tests/gateway/test_status.py

@@ -26,6 +26,22 @@ class TestGatewayPidState:
         assert status.get_running_pid() is None
         assert not pid_path.exists()
 
+    def test_get_running_pid_accepts_gateway_metadata_when_cmdline_unavailable(self, tmp_path, monkeypatch):
+        monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+        pid_path = tmp_path / "gateway.pid"
+        pid_path.write_text(json.dumps({
+            "pid": os.getpid(),
+            "kind": "hermes-gateway",
+            "argv": ["python", "-m", "hermes_cli.main", "gateway"],
+            "start_time": 123,
+        }))
+
+        monkeypatch.setattr(status.os, "kill", lambda pid, sig: None)
+        monkeypatch.setattr(status, "_get_process_start_time", lambda pid: 123)
+        monkeypatch.setattr(status, "_read_process_cmdline", lambda pid: None)
+
+        assert status.get_running_pid() == os.getpid()
+
 
 class TestGatewayRuntimeStatus:
     def test_write_runtime_status_records_platform_failure(self, tmp_path, monkeypatch):