fix(desktop): keep clarify visible in silent tool mode

[sanghyuk-seo-nexcube]

Summary

• Emit clarify tool lifecycle events even when display.tool_progress is off, so the Desktop inline clarify UI has a pending tool row to mount on.
• Keep ordinary tool lifecycle events hidden in silent mode.
• Add regression coverage for both the clarify exception and the non-blocking silent-mode invariant.

Test Plan

• python -m pytest tests/test_tui_gateway_server.py::test_clarify_lifecycle_emits_when_tool_progress_off tests/test_tui_gateway_server.py::test_non_blocking_tool_lifecycle_stays_hidden_when_tool_progress_off -q
• python -m py_compile tui_gateway/server.py tests/test_tui_gateway_server.py
• git diff --check

Notes

• I also ran scripts/run_tests.sh tests/test_tui_gateway_server.py; the new tests passed, but the file run hit an unrelated local environment failure in test_browser_manage_connect_default_local_reports_launch_hint where the expected “No supported Chromium-family browser executable was found” launch-hint line was not present.

[alt-glitch]

Duplicate of #47544 — both emit the clarify tool lifecycle (tool.start/tool.complete) when display.tool_progress=off while keeping ordinary tool events hidden, with near-identical regression tests in tests/test_tui_gateway_server.py. #47544 (opened ~4h earlier) is the broader fix: it also reconstructs a pending clarify row from clarify.request in apps/desktop use-message-stream.ts to cover the missed-tool.start reconnect/hydration race. Marking this as the narrower server-side subset; maintainer can pick whichever lands.