fix(web-ui): stabilize review and ACP settings flows

[limityan]

Summary

• Keep the Deep Review capacity queue notice visible when a terminal reviewer event still reports queued reviewers, preventing the waiting panel from disappearing and reappearing during review execution.
• Show the review action/result bar for completed Deep Review sessions even when the report has no remediation items, so users can confirm the finished review state.
• Stop the ACP Agents settings page from probing external CLIs on initial load or save; requirement checks now run only from the explicit Refresh action.

Root Cause

• Queue events are per reviewer, but the action-bar store treated a terminal event with an empty waiting list as meaning the whole queue was closed.
• The review completion path only opened the action bar when remediation items existed, even though the action bar already supports the no-issues completion state.
• ACP settings loaded requirement probes automatically, which can execute configured third-party CLIs such as opencode --version just by opening the page.

Validation

• pnpm run lint:web
• pnpm run type-check:web
• pnpm --dir src/web-ui run test:run