feat(desktop): TopBar connection status badge

[hqhq1025]

Summary

Implements §8.3 of docs/research/18-ux-master-plan.md.

• Adds a 10px status dot to the TopBar, immediately right of the project crumb
• Four states: green (connected), amber (untested/stale), red (error), grey (no provider)
• Hover tooltip shows state label, last-tested timestamp, error message, and "click to re-test" hint
• Clicking the dot triggers connection:v1:test-active IPC — reads active provider credentials from the encrypted keychain in the main process (no key passed from renderer)
• Auto-tests on mount when status is stale (>5 min old) or untested; dot is never animated
• New Zustand state slice: connectionStatus: { state, lastTestedAt, lastError } + setConnectionStatus + testConnection actions
• i18n keys added under topbar.status.* in en.json and zh-CN.json
• 13 new unit tests (6 store action tests + 7 component color/time-format tests); all 98 tests pass

Test plan

• typecheck passes (pnpm -r typecheck)
• lint passes with 0 errors (pnpm lint)
• all 98 tests pass (pnpm test)
• dot renders in TopBar next to crumb text
• amber on app start → auto-tests → turns green or red
• click dot → re-test fires → dot updates
• tooltip shows correct state label and last-tested time
• no dot rendered when no provider is configured

[github-actions]

Findings

• [Major] Renderer bridge failures are mislabeled as no_provider (silent misdiagnosis) — this hides IPC/preload breakage as a config issue, making real runtime failures harder to detect and violating the “no silent fallbacks” constraint. Evidence apps/desktop/src/renderer/src/store.ts:272
  Suggested fix:

  async testConnection() {
    const cfg = get().config;
    if (!window.codesign) {
      const msg = tr('errors.rendererDisconnected');
      set({
        connectionStatus: { state: 'error', lastTestedAt: Date.now(), lastError: msg },
        errorMessage: msg,
        lastError: msg,
      });
      return;
    }
    if (cfg === null || !cfg.hasKey || cfg.provider === null) {
      set({ connectionStatus: { state: 'no_provider', lastTestedAt: null, lastError: null } });
      return;
    }
    // ...
  }

• [Major] Relative time text is hardcoded in English and bypasses i18n — Chinese locale will still show "30s ago"/"3m ago", creating mixed-language UI. Evidence apps/desktop/src/renderer/src/components/ConnectionStatusDot.tsx:7
  Suggested fix:

  function formatRelativeTime(ts: number): string {
    const diffSec = Math.round((Date.now() - ts) / 1000);
    if (diffSec < 60) return t('topbar.status.relative.secondsAgo', { count: diffSec });
    const diffMin = Math.round(diffSec / 60);
    if (diffMin < 60) return t('topbar.status.relative.minutesAgo', { count: diffMin });
    return t('topbar.status.relative.hoursAgo', { count: Math.round(diffMin / 60) });
  }

• [Major] New UI uses raw pixel typography value text-[11px], which violates the token-only UI value constraint — this introduces a non-token size in app code. Evidence apps/desktop/src/renderer/src/components/ConnectionStatusDot.tsx:86
  Suggested fix:

  <span
    role="tooltip"
    className="... text-[var(--text-xs)] ..."
  >

• [Minor] “Component tests” do not exercise production component logic — test file redefines helper logic locally, so regressions in ConnectionStatusDot.tsx can pass undetected. Evidence apps/desktop/src/renderer/src/components/ConnectionStatusDot.test.ts:4
  Suggested fix:

  import { render, screen } from '@testing-library/react';
  import { ConnectionStatusDot } from './ConnectionStatusDot';
  
  it('renders localized last-tested tooltip', () => {
    render(<ConnectionStatusDot />);
    expect(screen.getByRole('button')).toHaveAttribute('aria-label', expect.stringContaining('Last tested'));
  });

Summary

• Review mode: initial
• 4 issues found in changed lines (3 Major, 1 Minor). No new dependency/license or direct provider SDK import issues found in this diff. docs/VISION.md and docs/PRINCIPLES.md are not present in this checkout (as noted by CLAUDE.md), so those docs could not be re-validated here.

Testing

• Not run (automation)

open-codesign Bot

[github-actions]

[Major] !window.codesign is mapped to no_provider, which masks renderer/main bridge failures as config state. Please surface this as an explicit error state (e.g., rendererDisconnected) instead of provider-missing.

[github-actions]

[Major] Relative-time text is hardcoded in English (s/m/h ago) and bypasses i18n, so zh-CN users will see mixed-language tooltip content. Please localize these units/phrases via translation keys.

[github-actions]

[Major] text-[11px] introduces a raw pixel typography value in app code. Per token-only UI constraints, use a tokenized text size (e.g., var(--text-*)) from packages/ui tokens.

[github-actions]

[Minor] This test file redefines helper logic locally instead of importing/testing the production component logic, so regressions in ConnectionStatusDot.tsx can slip through. Please switch to component-level assertions or exported helpers from the source file.