feat(desktop): surface language toggle

[Sun-sunshine06]

Summary

• initialize desktop i18n from the persisted locale before the renderer mounts
• expose a visible language toggle in both the top bar and onboarding flow
• localize shell copy that previously stayed hard-coded in English

Testing

• corepack pnpm --filter @open-codesign/desktop typecheck

[github-actions]

Findings

• [Major] Wiring registerLocaleIpc() makes locale persistence live, but that implementation currently writes to a hardcoded ~/.config/open-codesign/locale.json path. The repo explicitly says not to hard-code paths and to respect XDG / Electron path helpers, so this will diverge from non-default config roots. Evidence apps/desktop/src/main/index.ts:258, context apps/desktop/src/main/locale-ipc.ts:19.
  Suggested fix:

  import { join } from 'node:path';
  import { app } from './electron-runtime';
  
  const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

• [Major] The new locale IPC contract is unversioned (locale:get-system, locale:get-current, locale:set). docs/PRINCIPLES.md §5b requires every IPC channel to be versioned so future contract changes can ship side-by-side without breaking older renderers. Evidence apps/desktop/src/preload/index.ts:56.
  Suggested fix:

  const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
  const LOCALE_GET_CURRENT = 'locale:v1:get-current';
  const LOCALE_SET = 'locale:v1:set';

• [Minor] LanguageToggle introduces a hardcoded text-[12px] literal. UI values are supposed to come from packages/ui tokens, so this adds a new §8 violation on a freshly added component. Evidence apps/desktop/src/renderer/src/components/LanguageToggle.tsx:33.
  Suggested fix:

  className="... text-[var(--text-xs)] ..."

• [Minor] The newly modified top bar still hardcodes English tooltip/button copy, so switching to zh-CN leaves part of the shell untranslated even though this PR is specifically surfacing language switching. Evidence apps/desktop/src/renderer/src/components/TopBar.tsx:39.
  Suggested fix:

  <Tooltip label={t('commands.tooltips.commandPalette')}>
    <IconButton label={t('commands.items.openCommandPalette')} size="sm" onClick={openCommandPalette}>

Summary

• Review mode: initial. Four issues found: one path-handling regression activated by the new locale IPC wiring, one compatibility violation in the new IPC surface, and two renderer-level consistency issues in the new language toggle/top-bar UI.

Testing

• Not run (automation): this runner has no installed node_modules, so corepack pnpm --filter @open-codesign/desktop typecheck and corepack pnpm --filter @open-codesign/i18n test both failed before execution. No new Vitest/Playwright coverage was added for locale persistence, bootstrap, or translated shell copy.

open-codesign Bot

[github-actions]

Activating registerLocaleIpc() makes locale persistence live, but that implementation currently writes to a hardcoded ~/.config/open-codesign/locale.json path (apps/desktop/src/main/locale-ipc.ts:19). The repo explicitly says not to hard-code paths and to respect XDG / Electron path helpers. Can this be moved under app.getPath("userData") or the same config-dir helper used elsewhere?

Suggested fix:

import { join } from 'node:path';
import { app } from './electron-runtime';

const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

[github-actions]

These new locale IPC channels are unversioned (locale:get-system, locale:get-current, locale:set). docs/PRINCIPLES.md §5b requires every IPC channel to be versioned so protocol changes can ship side-by-side without breaking older renderers.

Suggested fix:

const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
const LOCALE_GET_CURRENT = 'locale:v1:get-current';
const LOCALE_SET = 'locale:v1:set';

[github-actions]

text-[12px] introduces a new hardcoded UI literal on a brand-new component. The repo rule is that visual values come from packages/ui tokens, so this should use an existing token or add one first.

Suggested fix:

className="... text-[var(--text-xs)] ..."

[github-actions]

This newly modified top-bar copy is still hardcoded in English, so switching to zh-CN leaves part of the shell untranslated even though this PR is about surfacing language switching. Can these strings move behind translation keys as well?

Suggested fix:

<Tooltip label={t('commands.tooltips.commandPalette')}>
  <IconButton label={t('commands.items.openCommandPalette')} size="sm" onClick={openCommandPalette}>

[github-actions]

Findings

• [Major] Locale persistence is now live, but the registered handler still writes to a hardcoded ~/.config/open-codesign/locale.json path. That bypasses Electron/XDG path helpers and directly violates the repo rule against hardcoded paths. Evidence apps/desktop/src/main/index.ts:258, context apps/desktop/src/main/locale-ipc.ts:19.
  Suggested fix:

  import { join } from 'node:path';
  import { app } from './electron-runtime';
  
  const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

• [Major] The new locale IPC surface is unversioned (locale:get-system, locale:get-current, locale:set). docs/PRINCIPLES.md §5b makes IPC versioning non-optional, so shipping these names as-is creates a compatibility contract we cannot evolve safely. Evidence apps/desktop/src/preload/index.ts:56.
  Suggested fix:

  const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
  const LOCALE_GET_CURRENT = 'locale:v1:get-current';
  const LOCALE_SET = 'locale:v1:set';

• [Major] The renderer now silently degrades when the preload bridge is missing: bootstrap falls back to the default locale and the toggle applies an in-memory change without persisting it. That violates §10's “no silent fallbacks” rule and turns a broken IPC bridge into a hard-to-debug “language reverted after restart” bug. Evidence apps/desktop/src/renderer/src/main.tsx:12, apps/desktop/src/renderer/src/components/LanguageToggle.tsx:24.
  Suggested fix:

  if (!window.codesign) {
    throw new Error('Locale bridge unavailable');
  }
  
  const locale = await window.codesign.locale.getCurrent();

• [Major] Surfacing LanguageToggle in onboarding exposes a language switch on a flow whose visible copy is still almost entirely hard-coded English (Welcome, PasteKey, ChooseModel). In zh-CN, users still see “Design with any model”, “Paste your API key”, “Pick default models”, etc., so the new onboarding toggle does not actually localize the screen it was added to. Evidence apps/desktop/src/renderer/src/onboarding/index.tsx:70, context apps/desktop/src/renderer/src/onboarding/Welcome.tsx:15, apps/desktop/src/renderer/src/onboarding/PasteKey.tsx:142, apps/desktop/src/renderer/src/onboarding/ChooseModel.tsx:50.
  Suggested fix:

  const t = useT();
  
  <h1>{t('onboarding.welcome.title')}</h1>
  <p>{t('onboarding.welcome.subtitle')}</p>

Summary

• Review mode: follow-up after new commits. Four issues found in the newly wired locale/onboarding surfaces: one path-handling regression, one IPC compatibility violation, one silent-fallback regression, and one onboarding-localization gap.

Testing

• Not run (automation): corepack pnpm --filter @open-codesign/desktop typecheck failed because node_modules are absent and the runner is on Node v20.20.2 while the repo requires >=22; corepack pnpm --filter @open-codesign/i18n test failed because vitest is unavailable without dependencies installed. No new Vitest/Playwright coverage was added for locale bootstrap, persistence, or the onboarding toggle.

open-codesign Bot

[github-actions]

Activating registerLocaleIpc() makes locale persistence live, but locale-ipc.ts still writes to a hardcoded ~/.config/open-codesign/locale.json path (apps/desktop/src/main/locale-ipc.ts:19). CLAUDE.md explicitly forbids hardcoded paths. Can this move under app.getPath("userData") or the same config-dir helper used elsewhere?

Suggested fix:

import { join } from 'node:path';
import { app } from './electron-runtime';

const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

[github-actions]

These new locale IPC channels are unversioned. docs/PRINCIPLES.md §5b requires every IPC contract to ship as vN so future renderer/main mismatches can coexist safely.

Suggested fix:

const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
const LOCALE_GET_CURRENT = 'locale:v1:get-current';
const LOCALE_SET = 'locale:v1:set';

[github-actions]

This boot path silently falls back when the preload bridge is missing. That means a broken locale IPC surface boots in the default language instead of failing loudly, and LanguageToggle has the same pattern when persisting. docs/PRINCIPLES.md §10 bans this kind of masked fallback.

Suggested fix:

if (!window.codesign) {
  throw new Error('Locale bridge unavailable');
}

const locale = await window.codesign.locale.getCurrent();

[github-actions]

Adding LanguageToggle here makes onboarding advertise language switching, but the actual onboarding copy is still hard-coded English in Welcome.tsx, PasteKey.tsx, and ChooseModel.tsx. In zh-CN, the user still sees "Design with any model", "Paste your API key", etc., so this new surface does not localize the screen it was added to.

Suggested fix:

const t = useT();

<h1>{t('onboarding.welcome.title')}</h1>
<p>{t('onboarding.welcome.subtitle')}</p>

[github-actions]

Findings

• [Major] Locale persistence still writes to a hardcoded ~/.config/open-codesign/locale.json path once this PR activates registerLocaleIpc(). That bypasses Electron/XDG path helpers and violates the repo rule against hardcoded paths. Evidence apps/desktop/src/main/index.ts:259, context apps/desktop/src/main/locale-ipc.ts:19.
  Suggested fix:

  import { join } from 'node:path';
  import { app } from './electron-runtime';
  
  const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

• [Major] The new locale bridge is still exposing unversioned IPC channels (locale:get-system, locale:get-current, locale:set). docs/PRINCIPLES.md §5b makes IPC versioning non-optional, so this ships a compatibility contract we cannot evolve safely. Evidence apps/desktop/src/preload/index.ts:56.
  Suggested fix:

  const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
  const LOCALE_GET_CURRENT = 'locale:v1:get-current';
  const LOCALE_SET = 'locale:v1:set';

• [Major] Locale bootstrap/toggling still silently falls back when the preload bridge is missing. main.tsx boots with undefined, and LanguageToggle applies the locale in memory without persistence, which violates PRINCIPLES §10 and makes a broken preload surface look like “language reverted after restart”. Evidence apps/desktop/src/renderer/src/main.tsx:12, apps/desktop/src/renderer/src/components/LanguageToggle.tsx:24.
  Suggested fix:

  if (!window.codesign) {
    throw new Error('Locale bridge unavailable');
  }
  
  const locale = await window.codesign.locale.getCurrent();
  const persisted = await window.codesign.locale.set(target);

• [Major] Onboarding now advertises a language switch, but the onboarding screens still render hard-coded English even though onboarding.* translations already exist in the locale bundles. In zh-CN, switching language still leaves Welcome, Paste your API key, and Pick default models untranslated, so the new surface does not localize the flow it was added to. Evidence apps/desktop/src/renderer/src/onboarding/index.tsx:70, context apps/desktop/src/renderer/src/onboarding/Welcome.tsx:14, apps/desktop/src/renderer/src/onboarding/PasteKey.tsx:141, apps/desktop/src/renderer/src/onboarding/ChooseModel.tsx:49, packages/i18n/src/locales/en.json:82.
  Suggested fix:

  const t = useT();
  
  <h1>{t('onboarding.welcome.title')}</h1>
  <p>{t('onboarding.welcome.subtitle')}</p>

Summary

• Review mode: follow-up after new commits. Four issues remain in the locale/onboarding path: hardcoded locale storage, unversioned IPC, silent bridge fallbacks, and an onboarding toggle that does not actually localize the onboarding flow.

Testing

• Not run (automation): node_modules/ is absent in this runner.
• Existing coverage only exercises packages/i18n/src/i18n.test.ts; no Vitest/Playwright coverage was added for Electron preload IPC, renderer bootstrap from persisted locale, or the onboarding toggle.

open-codesign Bot

[github-actions]

Activating registerLocaleIpc() makes locale persistence live, but locale-ipc.ts still writes to a hardcoded ~/.config/open-codesign/locale.json path (apps/desktop/src/main/locale-ipc.ts:19). CLAUDE.md forbids hardcoded paths. Can this move under app.getPath('userData')?

Suggested fix:

import { join } from 'node:path';
import { app } from './electron-runtime';

const LOCALE_FILE = join(app.getPath('userData'), 'locale.json');

[github-actions]

These locale IPC channels are still unversioned. docs/PRINCIPLES.md §5b requires every IPC contract to ship as vN so future renderer/main mismatches can coexist safely.

Suggested fix:

const LOCALE_GET_SYSTEM = 'locale:v1:get-system';
const LOCALE_GET_CURRENT = 'locale:v1:get-current';
const LOCALE_SET = 'locale:v1:set';

[github-actions]

This boot path still silently falls back when the preload bridge is missing, and LanguageToggle keeps the same pattern when persisting (apps/desktop/src/renderer/src/components/LanguageToggle.tsx:24). That turns a broken locale bridge into a quiet “language reverted after restart” bug.

Suggested fix:

if (!window.codesign) {
  throw new Error('Locale bridge unavailable');
}

const locale = await window.codesign.locale.getCurrent();
const persisted = await window.codesign.locale.set(target);

[github-actions]

Adding LanguageToggle here advertises locale switching, but the actual onboarding copy is still hard-coded English in Welcome.tsx, PasteKey.tsx, and ChooseModel.tsx, even though packages/i18n/src/locales/en.json / zh-CN.json already define onboarding.* keys. In zh-CN, this flow still renders English.

Suggested fix:

const t = useT();

<h1>{t('onboarding.welcome.title')}</h1>
<p>{t('onboarding.welcome.subtitle')}</p>