Register a shadow 'ask' tool that concurrently starts OMP's built-in
AskTool (terminal rendering, navigation, timeout, multi-question wizard)
and a blocking CodeIsland AskUserQuestion. Whichever side returns a real
answer first wins; the loser is cancelled immediately.

This replaces the previous flow where the extension handler blocked
inside tool_call until CodeIsland answered, delaying the terminal dialog
(wxtsky#244 -> wxtsky#256). Users can now answer from either the terminal or the
CodeIsland/iPhone/Watch UI without waiting for a handler timeout.

Key changes:
- Shadow ask reuses pi.pi.AskTool for its executor and LLM-facing
  label/description, preserving OMP's behavioral guidance.
- Bridge request carries _codeisland_native_ask_racing so AppState can
  scope Smart Suppress: only OMP requests with this marker may stay
  collapsed when the terminal is frontmost. Pi and legacy OMP keep the
  forced-expand fallback from wxtsky#256.
- Genuine native AskTool failure cancels the island bridge and
  propagates immediately instead of waiting for a 24h island timeout.
- Structured answer details (selectedOptions, customInput) are passed
  back via _codeislandAnswerDetails, scoped to pi source + toolUseId.
- QuestionBar preserves selectedOptions/customInput for all sources;
  non-OMP paths still consume the original answer string unchanged.
- multiSelect=true with empty/no options now shows a usable Submit
  button for free-text input (shared fix).
- HookEvent parses _pi_tool_call_id for OMP tool call correlation.
- OMP extension version bumped v2 -> v4.
- Native AskTool reuse probe, 20 AppStateQuestionFlowTests, and 9
  HookEventToolUseIdTests all pass.