Add Xquik search MCP server

[kriptoburak]

Summary

• Add an opt-in mcp-xquik-search example server built with ToolkitServer.
• Expose search_tweets, search_users, and get_trends using Xquik's public REST API.
• Wire the console script, README example list, and mocked HTTP tests.

Validation

• curl -LfsS https://xquik.com/openapi.json confirmed /api/v1/x/tweets/search, /api/v1/x/users/search, and /api/v1/x/trends.
• UV_PROJECT_ENVIRONMENT=/tmp/mcp-server-toolkit-xquik-venv uv run --python /Users/burak/.local/bin/python3.11 --extra dev pytest -q
• UV_PROJECT_ENVIRONMENT=/tmp/mcp-server-toolkit-xquik-venv uv run --python /Users/burak/.local/bin/python3.11 --extra dev pytest tests/test_xquik_search.py -q
• UV_PROJECT_ENVIRONMENT=/tmp/mcp-server-toolkit-xquik-venv-ruff uv run --python /Users/burak/.local/bin/python3.11 --extra dev ruff check src/mcp_server_toolkit/servers/xquik_search.py tests/test_xquik_search.py
• git diff --check