feat: Complete Bannerlord MCP Harness implementation (Issue #722)

Implements the Hermes observation/control path for local Bannerlord per GamePortal Protocol.

## New Components

- nexus/bannerlord_harness.py (874 lines)
  - MCPClient for JSON-RPC communication with MCP servers
  - capture_state() → GameState with visual + Steam context
  - execute_action() → ActionResult for all input types
  - observe-decide-act loop with telemetry through Hermes WS
  - Bannerlord-specific actions (inventory, party, save/load)
  - Mock mode for testing without game running

- mcp_servers/desktop_control_server.py (14KB)
  - 13 desktop automation tools via pyautogui
  - Screenshot, mouse, keyboard control
  - Headless environment support

- mcp_servers/steam_info_server.py (18KB)
  - 6 Steam Web API tools
  - Mock mode without API key, live mode with STEAM_API_KEY

- tests/test_bannerlord_harness.py (37 tests, all passing)
  - GameState/ActionResult validation
  - Mock mode action tests
  - ODA loop tests
  - GamePortal Protocol compliance tests

- docs/BANNERLORD_HARNESS_PROOF.md
  - Architecture documentation
  - Proof of ODA loop execution
  - Telemetry flow diagrams

- examples/harness_demo.py
  - Runnable demo showing full ODA loop

## Updates

- portals.json: Bannerlord metadata per GAMEPORTAL_PROTOCOL.md
  - status: active, portal_type: game-world
  - app_id: 261550, window_title: 'Mount & Blade II: Bannerlord'
  - telemetry_source: hermes-harness:bannerlord

## Verification

pytest tests/test_bannerlord_harness.py -v
37 passed, 2 skipped, 11 warnings

Closes #722

tests/conftest.py

@@ -0,0 +1,33 @@
+"""Pytest configuration for the test suite."""
+import pytest
+
+# Configure pytest-asyncio mode
+pytest_plugins = ["pytest_asyncio"]
+
+
+def pytest_configure(config):
+    """Configure pytest."""
+    config.addinivalue_line(
+        "markers", "integration: mark test as integration test (requires MCP servers)"
+    )
+
+
+def pytest_addoption(parser):
+    """Add custom command-line options."""
+    parser.addoption(
+        "--run-integration",
+        action="store_true",
+        default=False,
+        help="Run integration tests that require MCP servers",
+    )
+
+
+def pytest_collection_modifyitems(config, items):
+    """Modify test collection based on options."""
+    if not config.getoption("--run-integration"):
+        skip_integration = pytest.mark.skip(
+            reason="Integration tests require --run-integration and MCP servers running"
+        )
+        for item in items:
+            if "integration" in item.keywords:
+                item.add_marker(skip_integration)

tests/test_bannerlord_harness.py

@@ -0,0 +1,690 @@
+#!/usr/bin/env python3
+"""
+Bannerlord Harness Test Suite
+
+Comprehensive tests for the Bannerlord MCP Harness implementing the GamePortal Protocol.
+
+Test Categories:
+- Unit Tests: Test individual components in isolation
+- Mock Tests: Test without requiring Bannerlord or MCP servers running
+- Integration Tests: Test with actual MCP servers (skip if game not running)
+- ODA Loop Tests: Test the full Observe-Decide-Act cycle
+
+Usage:
+    pytest tests/test_bannerlord_harness.py -v
+    pytest tests/test_bannerlord_harness.py -v -k mock  # Only mock tests
+    pytest tests/test_bannerlord_harness.py -v --run-integration  # Include integration tests
+"""
+
+import asyncio
+import json
+import os
+import sys
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, Mock, patch
+
+import pytest
+
+# Ensure nexus module is importable
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from nexus.bannerlord_harness import (
+    BANNERLORD_APP_ID,
+    BANNERLORD_WINDOW_TITLE,
+    ActionResult,
+    BannerlordHarness,
+    GameContext,
+    GameState,
+    MCPClient,
+    VisualState,
+    simple_test_decision,
+)
+
+# Mark all tests in this file as asyncio
+pytestmark = pytest.mark.asyncio
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# FIXTURES
+# ═══════════════════════════════════════════════════════════════════════════
+
+@pytest.fixture
+def mock_mcp_client():
+    """Create a mock MCP client for testing."""
+    client = MagicMock(spec=MCPClient)
+    client.call_tool = AsyncMock(return_value="success")
+    client.list_tools = AsyncMock(return_value=["click", "press_key", "take_screenshot"])
+    client.start = AsyncMock(return_value=True)
+    client.stop = Mock()
+    return client
+
+
+@pytest.fixture
+def mock_harness():
+    """Create a BannerlordHarness in mock mode."""
+    harness = BannerlordHarness(enable_mock=True)
+    harness.session_id = "test-session-001"
+    return harness
+
+
+@pytest.fixture
+def mock_harness_with_ws():
+    """Create a mock harness with mocked WebSocket."""
+    harness = BannerlordHarness(enable_mock=True)
+    harness.session_id = "test-session-002"
+    harness.ws_connected = True
+    harness.ws = AsyncMock()
+    return harness
+
+
+@pytest.fixture
+def sample_game_state():
+    """Create a sample GameState for testing."""
+    return GameState(
+        portal_id="bannerlord",
+        session_id="test-session",
+        visual=VisualState(
+            screenshot_path="/tmp/test_capture.png",
+            screen_size=(1920, 1080),
+            mouse_position=(960, 540),
+            window_found=True,
+            window_title=BANNERLORD_WINDOW_TITLE,
+        ),
+        game_context=GameContext(
+            app_id=BANNERLORD_APP_ID,
+            playtime_hours=142.5,
+            achievements_unlocked=23,
+            achievements_total=96,
+            current_players_online=8421,
+            game_name="Mount & Blade II: Bannerlord",
+            is_running=True,
+        ),
+    )
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# GAME STATE DATA CLASS TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestGameState:
+    """Test GameState data class and serialization."""
+
+    def test_game_state_default_creation(self):
+        """Test creating a GameState with defaults."""
+        state = GameState()
+        assert state.portal_id == "bannerlord"
+        assert state.session_id is not None
+        assert len(state.session_id) == 8
+        assert state.timestamp is not None
+
+    def test_game_state_to_dict(self):
+        """Test GameState serialization to dict."""
+        state = GameState(
+            portal_id="bannerlord",
+            session_id="test1234",
+            visual=VisualState(
+                screenshot_path="/tmp/test.png",
+                screen_size=(1920, 1080),
+                mouse_position=(100, 200),
+                window_found=True,
+                window_title="Test Window",
+            ),
+            game_context=GameContext(
+                app_id=261550,
+                playtime_hours=10.5,
+                achievements_unlocked=5,
+                achievements_total=50,
+                current_players_online=1000,
+                game_name="Test Game",
+                is_running=True,
+            ),
+        )
+
+        d = state.to_dict()
+        assert d["portal_id"] == "bannerlord"
+        assert d["session_id"] == "test1234"
+        assert d["visual"]["screenshot_path"] == "/tmp/test.png"
+        assert d["visual"]["screen_size"] == [1920, 1080]
+        assert d["visual"]["mouse_position"] == [100, 200]
+        assert d["visual"]["window_found"] is True
+        assert d["game_context"]["app_id"] == 261550
+        assert d["game_context"]["playtime_hours"] == 10.5
+        assert d["game_context"]["is_running"] is True
+
+    def test_visual_state_defaults(self):
+        """Test VisualState default values."""
+        visual = VisualState()
+        assert visual.screenshot_path is None
+        assert visual.screen_size == (1920, 1080)
+        assert visual.mouse_position == (0, 0)
+        assert visual.window_found is False
+        assert visual.window_title == ""
+
+    def test_game_context_defaults(self):
+        """Test GameContext default values."""
+        context = GameContext()
+        assert context.app_id == BANNERLORD_APP_ID
+        assert context.playtime_hours == 0.0
+        assert context.achievements_unlocked == 0
+        assert context.achievements_total == 0
+        assert context.current_players_online == 0
+        assert context.game_name == "Mount & Blade II: Bannerlord"
+        assert context.is_running is False
+
+
+class TestActionResult:
+    """Test ActionResult data class."""
+
+    def test_action_result_default_creation(self):
+        """Test creating ActionResult with defaults."""
+        result = ActionResult()
+        assert result.success is False
+        assert result.action == ""
+        assert result.params == {}
+        assert result.error is None
+
+    def test_action_result_to_dict(self):
+        """Test ActionResult serialization."""
+        result = ActionResult(
+            success=True,
+            action="press_key",
+            params={"key": "space"},
+            error=None,
+        )
+        d = result.to_dict()
+        assert d["success"] is True
+        assert d["action"] == "press_key"
+        assert d["params"] == {"key": "space"}
+        assert "error" not in d
+
+    def test_action_result_with_error(self):
+        """Test ActionResult includes error when present."""
+        result = ActionResult(
+            success=False,
+            action="click",
+            params={"x": 100, "y": 200},
+            error="MCP server not running",
+        )
+        d = result.to_dict()
+        assert d["success"] is False
+        assert d["error"] == "MCP server not running"
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# BANNERLORD HARNESS UNIT TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestBannerlordHarnessUnit:
+    """Unit tests for BannerlordHarness."""
+
+    def test_harness_initialization(self):
+        """Test harness initializes with correct defaults."""
+        harness = BannerlordHarness()
+        assert harness.hermes_ws_url == "ws://localhost:8000/ws"
+        assert harness.enable_mock is False
+        assert harness.session_id is not None
+        assert len(harness.session_id) == 8
+        assert harness.desktop_mcp is None
+        assert harness.steam_mcp is None
+        assert harness.ws_connected is False
+
+    def test_harness_mock_mode_initialization(self):
+        """Test harness initializes correctly in mock mode."""
+        harness = BannerlordHarness(enable_mock=True)
+        assert harness.enable_mock is True
+        assert harness.desktop_mcp is None
+        assert harness.steam_mcp is None
+
+    async def test_capture_state_returns_gamestate(self, mock_harness):
+        """Test capture_state() returns a valid GameState object."""
+        state = await mock_harness.capture_state()
+
+        assert isinstance(state, GameState)
+        assert state.portal_id == "bannerlord"
+        assert state.session_id == "test-session-001"
+        assert "timestamp" in state.to_dict()
+
+    async def test_capture_state_includes_visual(self, mock_harness):
+        """Test capture_state() includes visual information."""
+        state = await mock_harness.capture_state()
+
+        assert isinstance(state.visual, VisualState)
+        assert state.visual.window_found is True
+        assert state.visual.window_title == BANNERLORD_WINDOW_TITLE
+        assert state.visual.screen_size == (1920, 1080)
+        assert state.visual.screenshot_path is not None
+
+    async def test_capture_state_includes_game_context(self, mock_harness):
+        """Test capture_state() includes game context."""
+        state = await mock_harness.capture_state()
+
+        assert isinstance(state.game_context, GameContext)
+        assert state.game_context.app_id == BANNERLORD_APP_ID
+        assert state.game_context.game_name == "Mount & Blade II: Bannerlord"
+        assert state.game_context.is_running is True
+        assert state.game_context.playtime_hours == 142.5
+        assert state.game_context.current_players_online == 8421
+
+    async def test_capture_state_sends_telemetry(self, mock_harness_with_ws):
+        """Test capture_state() sends telemetry when connected."""
+        harness = mock_harness_with_ws
+
+        await harness.capture_state()
+
+        # Verify telemetry was sent
+        assert harness.ws.send.called
+        call_args = harness.ws.send.call_args[0][0]
+        telemetry = json.loads(call_args)
+        assert telemetry["type"] == "game_state_captured"
+        assert telemetry["portal_id"] == "bannerlord"
+        assert telemetry["session_id"] == "test-session-002"
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# MOCK MODE TESTS (No external dependencies)
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestMockModeActions:
+    """Test harness actions in mock mode (no game/MCP required)."""
+
+    async def test_execute_action_click(self, mock_harness):
+        """Test click action in mock mode."""
+        result = await mock_harness.execute_action({
+            "type": "click",
+            "x": 100,
+            "y": 200,
+        })
+
+        assert isinstance(result, ActionResult)
+        assert result.success is True
+        assert result.action == "click"
+        assert result.params["x"] == 100
+        assert result.params["y"] == 200
+
+    async def test_execute_action_press_key(self, mock_harness):
+        """Test press_key action in mock mode."""
+        result = await mock_harness.execute_action({
+            "type": "press_key",
+            "key": "space",
+        })
+
+        assert result.success is True
+        assert result.action == "press_key"
+        assert result.params["key"] == "space"
+
+    async def test_execute_action_hotkey(self, mock_harness):
+        """Test hotkey action in mock mode."""
+        result = await mock_harness.execute_action({
+            "type": "hotkey",
+            "keys": "ctrl s",
+        })
+
+        assert result.success is True
+        assert result.action == "hotkey"
+        assert result.params["keys"] == "ctrl s"
+
+    async def test_execute_action_move_to(self, mock_harness):
+        """Test move_to action in mock mode."""
+        result = await mock_harness.execute_action({
+            "type": "move_to",
+            "x": 500,
+            "y": 600,
+        })
+
+        assert result.success is True
+        assert result.action == "move_to"
+
+    async def test_execute_action_type_text(self, mock_harness):
+        """Test type_text action in mock mode."""
+        result = await mock_harness.execute_action({
+            "type": "type_text",
+            "text": "Hello Bannerlord",
+        })
+
+        assert result.success is True
+        assert result.action == "type_text"
+        assert result.params["text"] == "Hello Bannerlord"
+
+    async def test_execute_action_unknown_type(self, mock_harness):
+        """Test handling of unknown action type."""
+        result = await mock_harness.execute_action({
+            "type": "unknown_action",
+            "param": "value",
+        })
+
+        # In mock mode, unknown actions still succeed but don't execute
+        assert isinstance(result, ActionResult)
+        assert result.action == "unknown_action"
+
+    async def test_execute_action_sends_telemetry(self, mock_harness_with_ws):
+        """Test action execution sends telemetry."""
+        harness = mock_harness_with_ws
+
+        await harness.execute_action({"type": "press_key", "key": "i"})
+
+        # Verify telemetry was sent
+        assert harness.ws.send.called
+        call_args = harness.ws.send.call_args[0][0]
+        telemetry = json.loads(call_args)
+        assert telemetry["type"] == "action_executed"
+        assert telemetry["action"] == "press_key"
+        assert telemetry["success"] is True
+
+
+class TestBannerlordSpecificActions:
+    """Test Bannerlord-specific convenience actions."""
+
+    async def test_open_inventory(self, mock_harness):
+        """Test open_inventory() sends 'i' key."""
+        result = await mock_harness.open_inventory()
+
+        assert result.success is True
+        assert result.action == "press_key"
+        assert result.params["key"] == "i"
+
+    async def test_open_character(self, mock_harness):
+        """Test open_character() sends 'c' key."""
+        result = await mock_harness.open_character()
+
+        assert result.success is True
+        assert result.action == "press_key"
+        assert result.params["key"] == "c"
+
+    async def test_open_party(self, mock_harness):
+        """Test open_party() sends 'p' key."""
+        result = await mock_harness.open_party()
+
+        assert result.success is True
+        assert result.action == "press_key"
+        assert result.params["key"] == "p"
+
+    async def test_save_game(self, mock_harness):
+        """Test save_game() sends Ctrl+S."""
+        result = await mock_harness.save_game()
+
+        assert result.success is True
+        assert result.action == "hotkey"
+        assert result.params["keys"] == "ctrl s"
+
+    async def test_load_game(self, mock_harness):
+        """Test load_game() sends Ctrl+L."""
+        result = await mock_harness.load_game()
+
+        assert result.success is True
+        assert result.action == "hotkey"
+        assert result.params["keys"] == "ctrl l"
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# ODA LOOP TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestODALoop:
+    """Test the Observe-Decide-Act loop."""
+
+    async def test_oda_loop_single_iteration(self, mock_harness):
+        """Test ODA loop completes one iteration."""
+        actions_executed = []
+
+        def decision_fn(state: GameState) -> list[dict]:
+            """Simple decision function for testing."""
+            return [
+                {"type": "move_to", "x": 100, "y": 100},
+                {"type": "press_key", "key": "space"},
+            ]
+
+        # Run for 1 iteration
+        await mock_harness.run_observe_decide_act_loop(
+            decision_fn=decision_fn,
+            max_iterations=1,
+            iteration_delay=0.1,
+        )
+
+        assert mock_harness.cycle_count == 0
+        assert mock_harness.running is True
+
+    async def test_oda_loop_multiple_iterations(self, mock_harness):
+        """Test ODA loop completes multiple iterations."""
+        iteration_count = [0]
+
+        def decision_fn(state: GameState) -> list[dict]:
+            iteration_count[0] += 1
+            return [{"type": "press_key", "key": "space"}]
+
+        await mock_harness.run_observe_decide_act_loop(
+            decision_fn=decision_fn,
+            max_iterations=3,
+            iteration_delay=0.01,
+        )
+
+        assert iteration_count[0] == 3
+        assert mock_harness.cycle_count == 2
+
+    async def test_oda_loop_empty_decisions(self, mock_harness):
+        """Test ODA loop handles empty decision list."""
+        def decision_fn(state: GameState) -> list[dict]:
+            return []
+
+        await mock_harness.run_observe_decide_act_loop(
+            decision_fn=decision_fn,
+            max_iterations=1,
+            iteration_delay=0.01,
+        )
+
+        # Should complete without errors
+        assert mock_harness.cycle_count == 0
+
+    def test_simple_test_decision_function(self, sample_game_state):
+        """Test the built-in simple_test_decision function."""
+        actions = simple_test_decision(sample_game_state)
+
+        assert len(actions) == 2
+        assert actions[0]["type"] == "move_to"
+        assert actions[0]["x"] == 960  # Center of 1920
+        assert actions[0]["y"] == 540  # Center of 1080
+        assert actions[1]["type"] == "press_key"
+        assert actions[1]["key"] == "space"
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# INTEGRATION TESTS (Require MCP servers or game running)
+# ═══════════════════════════════════════════════════════════════════════════
+
+def integration_test_enabled():
+    """Check if integration tests should run."""
+    return os.environ.get("RUN_INTEGRATION_TESTS") == "1"
+
+
+@pytest.mark.skipif(
+    not integration_test_enabled(),
+    reason="Integration tests require RUN_INTEGRATION_TESTS=1 and MCP servers running"
+)
+class TestIntegration:
+    """Integration tests requiring actual MCP servers."""
+
+    @pytest.fixture
+    async def real_harness(self):
+        """Create a real harness with MCP servers."""
+        harness = BannerlordHarness(enable_mock=False)
+        await harness.start()
+        yield harness
+        await harness.stop()
+
+    async def test_real_capture_state(self, real_harness):
+        """Test capture_state with real MCP servers."""
+        state = await real_harness.capture_state()
+
+        assert isinstance(state, GameState)
+        assert state.portal_id == "bannerlord"
+        assert state.visual.screen_size[0] > 0
+        assert state.visual.screen_size[1] > 0
+
+    async def test_real_execute_action(self, real_harness):
+        """Test execute_action with real MCP server."""
+        # Move mouse to safe position
+        result = await real_harness.execute_action({
+            "type": "move_to",
+            "x": 100,
+            "y": 100,
+        })
+
+        assert result.success is True
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# MCP CLIENT TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestMCPClient:
+    """Test the MCPClient class."""
+
+    def test_mcp_client_initialization(self):
+        """Test MCPClient initializes correctly."""
+        client = MCPClient("test-server", ["npx", "test-mcp"])
+
+        assert client.name == "test-server"
+        assert client.command == ["npx", "test-mcp"]
+        assert client.process is None
+        assert client.request_id == 0
+
+    async def test_mcp_client_call_tool_not_running(self):
+        """Test calling tool when server not started."""
+        client = MCPClient("test-server", ["npx", "test-mcp"])
+
+        result = await client.call_tool("click", {"x": 100, "y": 200})
+
+        assert "error" in result
+        assert "not running" in str(result).lower()
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# TELEMETRY TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestTelemetry:
+    """Test telemetry sending functionality."""
+
+    async def test_telemetry_sent_on_state_capture(self, mock_harness_with_ws):
+        """Test telemetry is sent when state is captured."""
+        harness = mock_harness_with_ws
+
+        await harness.capture_state()
+
+        # Should send game_state_captured telemetry
+        calls = harness.ws.send.call_args_list
+        telemetry_types = [json.loads(c[0][0])["type"] for c in calls]
+        assert "game_state_captured" in telemetry_types
+
+    async def test_telemetry_sent_on_action(self, mock_harness_with_ws):
+        """Test telemetry is sent when action is executed."""
+        harness = mock_harness_with_ws
+
+        await harness.execute_action({"type": "press_key", "key": "space"})
+
+        # Should send action_executed telemetry
+        calls = harness.ws.send.call_args_list
+        telemetry_types = [json.loads(c[0][0])["type"] for c in calls]
+        assert "action_executed" in telemetry_types
+
+    async def test_telemetry_not_sent_when_disconnected(self, mock_harness):
+        """Test telemetry is not sent when WebSocket disconnected."""
+        harness = mock_harness
+        harness.ws_connected = False
+        harness.ws = AsyncMock()
+
+        await harness.capture_state()
+
+        # Should not send telemetry when disconnected
+        assert not harness.ws.send.called
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# GAMEPORTAL PROTOCOL COMPLIANCE TESTS
+# ═══════════════════════════════════════════════════════════════════════════
+
+class TestGamePortalProtocolCompliance:
+    """Test compliance with the GamePortal Protocol specification."""
+
+    async def test_capture_state_returns_valid_schema(self, mock_harness):
+        """Test capture_state returns valid GamePortal Protocol schema."""
+        state = await mock_harness.capture_state()
+        data = state.to_dict()
+
+        # Required fields per GAMEPORTAL_PROTOCOL.md
+        assert "portal_id" in data
+        assert "timestamp" in data
+        assert "session_id" in data
+        assert "visual" in data
+        assert "game_context" in data
+
+        # Visual sub-fields
+        visual = data["visual"]
+        assert "screenshot_path" in visual
+        assert "screen_size" in visual
+        assert "mouse_position" in visual
+        assert "window_found" in visual
+        assert "window_title" in visual
+
+        # Game context sub-fields
+        context = data["game_context"]
+        assert "app_id" in context
+        assert "playtime_hours" in context
+        assert "achievements_unlocked" in context
+        assert "achievements_total" in context
+        assert "current_players_online" in context
+        assert "game_name" in context
+        assert "is_running" in context
+
+    async def test_execute_action_returns_valid_schema(self, mock_harness):
+        """Test execute_action returns valid ActionResult schema."""
+        result = await mock_harness.execute_action({
+            "type": "press_key",
+            "key": "space",
+        })
+        data = result.to_dict()
+
+        # Required fields per GAMEPORTAL_PROTOCOL.md
+        assert "success" in data
+        assert "action" in data
+        assert "params" in data
+        assert "timestamp" in data
+
+    async def test_all_action_types_supported(self, mock_harness):
+        """Test all GamePortal Protocol action types are supported."""
+        action_types = [
+            "click",
+            "right_click",
+            "double_click",
+            "move_to",
+            "drag_to",
+            "press_key",
+            "hotkey",
+            "type_text",
+            "scroll",
+        ]
+
+        for action_type in action_types:
+            action = {"type": action_type}
+            # Add required params based on action type
+            if action_type in ["click", "right_click", "double_click", "move_to", "drag_to"]:
+                action["x"] = 100
+                action["y"] = 200
+            elif action_type == "press_key":
+                action["key"] = "space"
+            elif action_type == "hotkey":
+                action["keys"] = "ctrl s"
+            elif action_type == "type_text":
+                action["text"] = "test"
+            elif action_type == "scroll":
+                action["amount"] = 3
+
+            result = await mock_harness.execute_action(action)
+            assert isinstance(result, ActionResult), f"Action {action_type} failed"
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# MAIN ENTRYPOINT
+# ═══════════════════════════════════════════════════════════════════════════
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])