fix: recover local workflows and nonmodal prompts

[ken-jo]

Summary

• recover the Local Indexer Python runtime with a cache-preserving first sync and a bounded Windows no-cache/copy fallback, while keeping sentinel and retry behavior fail-safe
• make ask_user_question choice-only end to end: validate request-bound choices, preserve FIFO state, reject malformed or duplicate options, and retain legacy transcript reads without exposing manual input
• render foreground approvals as a route-local floating bottom dock that does not consume layout space, stays clear of the composer/question dock, and keeps background navigation interactive
• remove obsolete floating-question/manual-input artifacts, align current docs and translations, and refresh the public choice-only screenshot

Preserved contracts

• no foreground approval dialog, backdrop, focus trap, inert, or body scroll lock
• approval decisions and rationale sealing remain fail-closed
• user cache overrides are honored on the normal Python sync path; fallback runs once only after a Windows cache-related failure
• legacy stored freeText remains read-only transcript compatibility; live renderer/preload/IPC response boundaries are choice-only

Validation

• pre-push: 1,012 test files passed, 1 skipped; 12,885 tests passed, 43 skipped
• focused Vitest: 9 files / 276 tests; IPC error formatter: 2 files / 14 tests
• Electron E2E: question interaction/layout + approval dock 8/8; navigation/Insights/Settings CDP 4/4
• bun run typecheck, test type baseline/self-test, Knip baseline, duplicate helper policy, i18n catalog/barrels, source-text-safe, diff check, and full build
• isolated plugin boot: Local Indexer and Meeting load/start successfully; public screenshot contains no manual-input field or stale Doctor state