Add birdcage-mcp FastMCP server for satellite dish control

34 tools (connection, movement, signal, system, satellite, console),
5 resources, 3 prompts. Backed by DemoDevice for offline testing.
46 tests passing against the demo backend via run_server_async.

mcp/tests/conftest.py

@@ -0,0 +1,74 @@
+"""Shared fixtures for birdcage-mcp tests.
+
+Uses FastMCP's run_server_async to spin up a real MCP server backed by
+DemoDevice + DemoCraftClient. No serial hardware, no subprocesses.
+"""
+
+import json
+from contextlib import asynccontextmanager
+
+import pytest
+from birdcage.demo import DemoCraftClient, DemoDevice
+from fastmcp import Client, FastMCP
+from fastmcp.client.transports import StreamableHttpTransport
+from fastmcp.utilities.tests import run_server_async
+
+from birdcage_mcp.state import BirdcageState
+
+
+@asynccontextmanager
+async def _test_lifespan(server: FastMCP):
+    """Test lifespan that pre-connects a DemoDevice."""
+    device = DemoDevice()
+    device.connect()
+    device.initialize()
+
+    state = BirdcageState(
+        device=device,
+        craft_client=DemoCraftClient(),
+        demo_mode=True,
+        serial_port="/dev/demo",
+        firmware_name="g2",
+        connected=True,
+    )
+    yield state
+
+
+def _build_server() -> FastMCP:
+    """Build a FastMCP server with all tools registered."""
+    from birdcage_mcp import prompts, resources
+    from birdcage_mcp.tools import (
+        connection,
+        console,
+        movement,
+        satellite,
+        signal,
+        system,
+    )
+
+    mcp = FastMCP("birdcage-test", lifespan=_test_lifespan)
+    connection.register(mcp)
+    movement.register(mcp)
+    signal.register(mcp)
+    system.register(mcp)
+    satellite.register(mcp)
+    console.register(mcp)
+    resources.register(mcp)
+    prompts.register(mcp)
+    return mcp
+
+
+@pytest.fixture
+async def mcp_client():
+    """Yield a connected MCP client backed by DemoDevice."""
+    server = _build_server()
+    async with (
+        run_server_async(server) as url,
+        Client(StreamableHttpTransport(url)) as client,
+    ):
+        yield client
+
+
+def parse_result(result) -> dict:
+    """Extract the dict from a tool call result."""
+    return json.loads(result.content[0].text)