feat(i18n): wire hardcoded settings surfaces (MoA, Billing, Custom Endpoints) for all locales

[anatolijlaptev1991-ctrl]

Summary

Three settings surfaces in the Desktop app contained hard-coded English strings that bypassed the i18n system entirely:

1. Model Settings → Mixture of Agents (model-settings.tsx) — 13 literals
2. Custom Endpoints (custom-endpoints-settings.tsx) — 28 literals
3. Billing panel (billing/index.tsx, plans-view.tsx, current-plan-card.tsx, auto-reload-row.tsx, use-billing-state.ts, errors.ts) — 75+ literals

These surfaces rendered English for every locale, including zh and ja. This PR wires them to the i18n system with t() / translateNow() calls and adds the corresponding keys to en.ts + the Translations interface.

Locale-neutral: no ru.ts, no catalog.ts/languages.ts changes, no new locale registration. This benefits every existing and future locale equally.

Extracted from #71573 per maintainer feedback (comment) to split the generic wiring from the Russian catalog.

Changes

• model-settings.tsx — MoA: title, description, preset, enabled, setDefault, delete, newPreset, addPreset, defaultLabel, referenceN, remove, addReference, aggregator
• custom-endpoints-settings.tsx — all field labels, buttons, notifications (28 strings)
• billing/index.tsx + plans-view.tsx — Billing, Plan, Payment & credits, Usage, portal, auto-refill, Confirm downgrade
• billing/use-billing-state.ts — usage panel: subscription credits, top-up credits, monthly spend cap, does not expire, refill when low, payment method, etc. (40+ strings)
• billing/errors.ts — error banners: card confirmation needed, monthly spend cap reached, remote spending needs approval, session logged out, admin role required, etc. (35+ strings)
• en.ts — 257 new keys across settings.model.moa, settings.billing.*, settings.customEndpoints.*
• types.ts — corresponding Translations interface extensions

Sweeper review (addressed)

All five issues from the hermes-sweeper review are fixed in d65de924 (rebased on main @ f3cda0ceb):

1. Removed type fields (sayStopToEnd, findInPage, artifactCard, quickEntry, wakeWord*) — restored from main type contract. types.ts rebuilt from main, then new keys added on top.
2. zh.ts catalog — all new keys added (flat naming: moaTitle, moaDesc, etc.) with Chinese translations or English fallback.
3. AUTO_REFILL_GENERIC — module-level const removed; translation moved into view-building path (use-billing-state.ts), now reactive to locale changes.
4. Remaining literals — errors.ts:48 recovery suffix, auto-reload-row.tsx:98, model-settings.tsx:1109 aria-label — all wired.
5. Type contract — zh.ts + types.ts fully consistent.

Verification (fresh, on committed d65de924):

• tsc clean (3 tsconfigs, 0 errors)
• ESLint clean (0 errors, 8 pre-existing warnings)
• test:ui -- i18n 28/28 passed
• test:ui -- billing 105/107 (2 pre-existing failures on unchanged billing-amounts.ts)

Verification

• tsc clean on all 3 tsconfigs (renderer, electron, e2e)
• ESLint clean
• npm run build (vite production build) succeeds
• Idempotent: re-running the wiring produces no-op (detect by presence of t('settings.model.moa.title'))

Relation to other PRs

• feat(desktop): add Russian (ru) locale — merged catalog, 2755 keys, 100% coverage #71573 — the original combined PR (locale + wiring). Per maintainer suggestion, this wiring is extracted here.
• feat(i18n): add complete Russian desktop locale #72250 — DrMaks22's Russian locale PR. This wiring is complementary: once it lands, feat(i18n): add complete Russian desktop locale #72250 (or any locale PR) gets these surfaces translated automatically.
• feat(desktop): added Russian language #40701 — earlier Russian locale PR (~34% coverage).

This PR has no conflicts with any locale catalog.

[teknium1]

Thanks for isolating the wiring work; the underlying issue is real on current main (model-settings.tsx:1004, custom-endpoints-settings.tsx:232, and billing/errors.ts:28-29 still render literals).

Problems

• The added required Translations keys (apps/desktop/src/i18n/types.ts:687) have no counterparts in the unchanged full Chinese catalog (apps/desktop/src/i18n/zh.ts:5). The PR head therefore cannot meet that catalog's type contract. It also removes unrelated type members such as sayStopToEnd; current main still requires that member at types.ts:198.
• AUTO_REFILL_GENERIC is translated once at module initialization (billing/use-billing-state.ts:604). translateNow() reads the mutable runtime locale (src/i18n/runtime.ts:54-65), so this copy does not change after the user switches locale.
• Several literals remain in the claimed surfaces, including the recovery suffix in billing/errors.ts:48, AutoReloadRow copy at billing/auto-reload-row.tsx:98, and the MoA switch aria-label at model-settings.tsx:1109.

Suggested changes

• Preserve existing type fields, add the new keys to every locale catalog, and translate the remaining billing/MoA literals.
• Move the auto-refill generic translation into the view-building path and add a non-English render test.

This is an automated hermes-sweeper review.

[teknium1]

These required additions need matching catalog entries. zh.ts declares a complete Translations object directly, but this PR does not change it and its head has no moaTitle, customEndpoints, or billing additions; preserve the existing interface members and update every locale catalog.

[teknium1]

translateNow() reads the mutable runtime locale, so resolving this at module import permanently captures the initial language. Move this lookup into autoReloadRow() or otherwise recompute it when building the view.

[anatolijlaptev1991-ctrl]

Thanks for the review — all five issues are addressed in d65de924e (rebased onto main @ f3cda0ceb).

1. Removed type fields (sayStopToEnd etc.) — types.ts was rebuilt from the main type contract, then the new moa/customEndpoints/billing keys were added on top. sayStopToEnd, findInPage, artifactCard, quickEntry, wakeWord*, and every other member removed in the prior head are restored. tsc confirms the full catalog compiles.

2. zh.ts missing new keys — all new keys (moa/customEndpoints/billing/state/errors, incl. remoteSpendingReconnect, moaDisableRef/moaEnableRef) are added to zh.ts with Chinese translations. The full Translations-typed catalog now compiles.

3. AUTO_REFILL_GENERIC frozen at module init — the module-level const AUTO_REFILL_GENERIC = translateNow(...) is removed; the translation now reads the runtime locale inside the view-building path (autoReloadRow()), so it updates after a locale switch.

4. Remaining literals translated:

• errors.ts reconnect suffix → translateNow('settings.billing.errors.remoteSpendingReconnect', who)
• auto-reload-row.tsx 'Auto-refill updated.' → translateNow('settings.billing.autoReload.updated')
• model-settings.tsx MoA switch aria-label → t.settings.model.moaDisableRef(n) / moaEnableRef(n)

Checks (all green):

• npm run typecheck — 3 tsconfig, 0 errors
• eslint src/app/settings/ src/i18n/ — 0 errors (8 pre-existing warnings)
• npm run test:ui -- i18n — 28/28 passed
• npm run test:ui -- src/app/settings/billing — 105/107 passed; the 2 failures are pre-existing on origin/main (verified via a clean main worktree), unrelated to this PR

[anatolijlaptev1991-ctrl]

Follow-up: 3-independent-auditor review (0c6ad7789)

After the initial sweeper feedback, ran two rounds of 3 independent auditor agents (types/contracts, literals/UX, tests/style) to scrupulously find every remaining issue. Round 1 found 5 real issues — all fixed and verified. Round 2 confirmed clean.

Round 1 findings — fixed in 0c6ad7789

ID	Severity	Issue	Fix
B1	BLOCKER	rateLimited/stripeUnavailable passed a pre-formatted English string "(try again in ~5 min)" as mins parameter — it leaked into Chinese as "请在 (try again in ~5 min) 分钟后重试"	Changed mins from string → number (minute count). Each locale now formats its own retry suffix via ternary mins > 0 ? … : …. Signature updated in types.ts, en.ts, zh.ts.
B2	BLOCKER	useSubscriptionState wasn't subscribed to locale changes — deriveBillingView could render stale translations for up to 30s (poll interval) after locale switch	Added useI18n() to useSubscriptionState, matching useBillingState.
M2	MAJOR	auto-reload-row.tsx — 12 hardcoded English literals (Threshold, Reload to, Turn off, Disable, Save, Saving…, Cancel, Manage, Auto-refill turned off, etc.) despite keys already existing in the catalog	All 12 wired to translateNow('settings.billing.autoReload.*'). Added thresholdAria/reloadToAria keys for the two aria-labels.
M3	MAJOR	plans-view.tsx — "Current plan", "Scheduled", "Downgrade" hardcoded despite bp.current/bp.scheduled/bp.downgrade existing	All 3 wired to existing bp.* keys.
N1	MINOR	provenanceSuffix — 3 hardcoded English provenance labels ("auto-refill card", "customer default", "subscription card")	Added paymentMethod.provenance.* keys to types/en/zh; wired via 4 translateNow() calls.

Verification (all green)

• tsc -p . --noEmit — 0 errors (all 3 tsconfig configs)
• eslint src/app/settings/ src/i18n/ — 0 errors (8 pre-existing warnings, all outside PR hunks)
• vitest billing + i18n — 133/135 passed; 2 failures are pre-existing on upstream/main (verified via git checkout upstream/main + rerun — Intl.NumberFormat renders "10 $" instead of "$10" on non-en-US hosts; unrelated to i18n wiring, needs a separate billing-amounts fix)
• CRLF — 0 contaminated files (en.ts normalized to LF in 3e570ee0e)
• Diff scope — exactly 11 files, 0 out-of-scope

Round 2 — clean ✅

Three fresh auditors on HEAD 0c6ad7789 confirmed: all 5 round-1 fixes verified working, no new BLOCKER/MAJOR/MINOR findings. The only observation was a stylistic NIT (ASCII -> in en.ts vs Unicode → in zh.ts for remoteSpendingReconnect) — both are valid, just a convention difference.

[anatolijlaptev1991-ctrl]

Rebased onto current upstream/main — conflicts resolved

The branch was 2746 commits behind main and reporting CONFLICTING/DIRTY. I rebuilt it on top of the current main (the i18n architecture changed since July 30: locales are now built via defineLocale, and ar/ja/zh-hant catalogs were added).

What changed

• Rebased the wiring onto main (now behind: 0, ahead: 1).
• en.ts + types.ts: added the full moa* / customEndpoints / billing.* key sets the components consume (incl. thresholdAria, reloadToAria, moaDisableRef/moaEnableRef, provenance.customerDefault/subPin/suffix, remoteSpendingReconnect).
• zh.ts: complete Chinese translations for the new key sets (it's a strict Translations catalog, so it must implement every key). ja/zh-hant/ar inherit from en via defineLocale, so they need no edits.
• index.test.tsx: fixed an import (react-router-dom → react-router).

Verification (real, on the pushed commit)

• tsc clean on all 3 tsconfigs (renderer, electron, e2e) — 0 errors.
• vitest ui: i18n 28/28 passing; billing 133/135.
• The 2 billing failures (rejects auto-refill amounts…, disables buy controls while polling…) are pre-existing on upstream/main — confirmed by running the same suite on a clean main checkout (105/107). Unrelated to this wiring.

Remaining gate: an approving review (mergeStateStatus: BLOCKED is only the missing approval, not a conflict — mergeable is now MERGEABLE).

This is locale-neutral: once merged, every locale (existing or future) gets these surfaces translated automatically, complementary to any ru catalog PR (#72250, #40701).