feat(resources): add unraid://live/{action} MCP resources for 9 snapshot subscriptions

Registers cpu, memory, cpu_telemetry, array_state, parity_progress,
ups_status, notifications_overview, owner, and server_status as MCP
resources under unraid://live/{action}. Each opens a transient WebSocket
via subscribe_once() and returns JSON; exceptions degrade gracefully to
an error JSON dict rather than raising. Skips log_tail and
notification_feed (require params, not suitable as resources).

tests/test_resources.py

@@ -0,0 +1,97 @@
+"""Tests for MCP subscription resources."""
+
+import json
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from fastmcp import FastMCP
+
+from unraid_mcp.subscriptions.resources import register_subscription_resources
+
+
+def _make_resources():
+    """Register resources on a test FastMCP instance and return it."""
+    test_mcp = FastMCP("test")
+    register_subscription_resources(test_mcp)
+    return test_mcp
+
+
+@pytest.fixture
+def _mock_subscribe_once():
+    with patch(
+        "unraid_mcp.subscriptions.resources.subscribe_once",
+        new_callable=AsyncMock,
+    ) as mock:
+        yield mock
+
+
+@pytest.fixture
+def _mock_ensure_started():
+    with patch(
+        "unraid_mcp.subscriptions.resources.ensure_subscriptions_started",
+        new_callable=AsyncMock,
+    ) as mock:
+        yield mock
+
+
+class TestLiveResources:
+    @pytest.mark.parametrize(
+        "action",
+        [
+            "cpu",
+            "memory",
+            "cpu_telemetry",
+            "array_state",
+            "parity_progress",
+            "ups_status",
+            "notifications_overview",
+            "owner",
+            "server_status",
+        ],
+    )
+    async def test_resource_returns_json(
+        self,
+        action: str,
+        _mock_subscribe_once: AsyncMock,
+        _mock_ensure_started: AsyncMock,
+    ) -> None:
+        _mock_subscribe_once.return_value = {"data": "ok"}
+        mcp = _make_resources()
+
+        local_provider = mcp.providers[0]
+        resource_key = f"resource:unraid://live/{action}@"
+        resource = local_provider._components[resource_key]
+        result = await resource.fn()
+
+        parsed = json.loads(result)
+        assert parsed == {"data": "ok"}
+
+    async def test_resource_returns_error_dict_on_failure(
+        self,
+        _mock_subscribe_once: AsyncMock,
+        _mock_ensure_started: AsyncMock,
+    ) -> None:
+        from fastmcp.exceptions import ToolError
+
+        _mock_subscribe_once.side_effect = ToolError("WebSocket timeout")
+        mcp = _make_resources()
+
+        local_provider = mcp.providers[0]
+        resource = local_provider._components["resource:unraid://live/cpu@"]
+        result = await resource.fn()
+
+        parsed = json.loads(result)
+        assert "error" in parsed
+        assert "WebSocket timeout" in parsed["error"]
+
+
+class TestLogsStreamResource:
+    async def test_logs_stream_no_data(self, _mock_ensure_started: AsyncMock) -> None:
+        with patch("unraid_mcp.subscriptions.resources.subscription_manager") as mock_mgr:
+            mock_mgr.get_resource_data = AsyncMock(return_value=None)
+            mcp = _make_resources()
+            local_provider = mcp.providers[0]
+            resource = local_provider._components["resource:unraid://logs/stream@"]
+            result = await resource.fn()
+            parsed = json.loads(result)
+            assert "status" in parsed