chore(mcp): remove unused imports in trustgraph-mcp

Closes #784.

ruff F401 pass on `trustgraph-mcp/trustgraph/mcp_server/`:

- `tg_socket.py` — drop `dataclasses.dataclass` and `time` (the example
  called out in the issue; neither is referenced anywhere in the file).
- `mcp.py` — drop five additional unused imports surfaced by ruff in
  the same directory: `typing.Optional`, `time`, `typing.AsyncGenerator`,
  `asyncio`, `uuid`, `mcp.types.TextContent`, and
  `websockets.asyncio.client.connect`.

Scope is limited to the mcp_server directory — seven F401 hits, all
autofixable. Other packages in the monorepo have more F401 warnings
that can be cleaned up in follow-up PRs to keep this one reviewable.

`ruff check --select F401 trustgraph-mcp/trustgraph/mcp_server/` is
clean after the change.

trustgraph-mcp/trustgraph/mcp_server/mcp.py

@@ -1,20 +1,14 @@
 from contextlib import asynccontextmanager
-from typing import Optional
 import os
-import time
-from typing import AsyncGenerator, Any, Dict, List
-import asyncio
+from typing import Any, Dict, List
 import logging
 import json
-import uuid
 import argparse
 from dataclasses import dataclass
 from collections.abc import AsyncIterator
 from functools import partial
 
 from mcp.server.fastmcp import FastMCP, Context
-from mcp.types import TextContent
-from websockets.asyncio.client import connect
 
 from trustgraph.base.logging import add_logging_args, setup_logging
 

trustgraph-mcp/trustgraph/mcp_server/tg_socket.py

@@ -1,12 +1,10 @@
 
-from dataclasses import dataclass
 from websockets.asyncio.client import connect
 from urllib.parse import urlencode, urlparse, urlunparse, parse_qs
 import asyncio
 import logging
 import json
 import uuid
-import time
 
 class WebSocketManager: