* feat(gui): add Sub2API balance autofill
Offer Sub2API alongside NewAPI in the custom provider's balance-token hint.
Fill /api/v1/user/profile and $data.balance, and describe both endpoints in
the existing translations.
Verified: native macOS build; 10 existing browser and translation checks;
Sub2API flows in Chromium and WebKit, four languages, at 900px and 440px;
live web assets. The original code fails the temporary two-shortcut check.
Full Go suite, cross-platform builds and live-account validation not run.
* fix(gui): preserve custom balance fields in account shortcuts
Use the same replacement rule for both account balance shortcuts, keeping
user-written expressions. Describe both endpoints in the key-only URL
warning and restore the rationale for flagging missing and key-only URLs.
Add browser cases for both URL states, new providers, saved form values,
narrow layouts and all four languages.
Validation: 111/111 related checks across Chromium and WebKit; native macOS
build; 38/38 after baseline failure checks. New button cases fail against
d9b2cdc5 app.js, and custom-field checks fail against cf3f3d9d app.js.
Full Go suite, cross-platform builds and live-account validation not run.