Add load_toolset to the compact tool lists in streaming.rs and
ui_writer_impl.rs so it renders as a single-line summary instead of
the full multi-line tool definitions output.
Summary format:
🧩 loaded '<name>' — on success
ℹ️ already loaded — when already loaded
❌ failed — on error
The toolset name arg is extracted as display_arg in print_tool_compact
so it appears in the compact output line.