Add MCP server support (#1137)

* add a generic MCP client and a config for connecting MCP servers

* Add MCP docs and CLI polish: docs page, startup connect summary, --mcp-config flag, compact tool output

* Add MCP connection notes and per-run selection; clean up on cancel and dedupe names

* Show errored MCP tool calls as failed in the TUI

* Sanitize namespaced tool names so model APIs accept them

* Show MCP tool calls distinctly in the terminal and the run viewer

* Say what MCP servers are worth connecting for

* Correct the notes docstring to match how notes reach the agent

* keep the mcp tests from reading your shell's STRIX_MCP_* vars

pyproject.toml

@@ -241,6 +241,8 @@ ignore = [
 "tests/test_stream_idle_timeout.py" = ["N802", "SLF001"]
 "tests/test_unknown_tool_recovery.py" = ["N802"]
 "tests/test_report_pdf.py" = ["S105", "S106"]
+# Fake MCP server matches the SDK's MCPServer signature; its args are unused.
+"tests/test_mcp_client.py" = ["S105", "S106", "ARG002"]
 # Stdlib HTTP handler overrides (do_GET/do_POST) and lazy imports that avoid a
 # circular dependency with strix.telemetry / strix.interface.viewer.report_pdf.
 "strix/interface/viewer/server.py" = ["N802", "PLC0415"]