i18n: Italian can't be auto-selected (Supernote reports en_US; region/handwriting not exposed)

[gorlix]

Problem

The plugin can't automatically show Italian, even on a device used in Italy, because the Supernote does not expose an "Italian" signal to plugins.

Evidence (on-device probe, A5X2 / SN100C10012377)

With the device UI in English, region Italy, handwriting recognition Italian:

I18nManager.localeIdentifier = en_US
Intl.DateTimeFormat().resolvedOptions().locale = en-US
NativeModules (keys matching lang|locale|i18n|setting) = []   // none

So the only locale signal available to the plugin is en_US. The region (Italy) and handwriting-recognition language (Italian) are internal Supernote app settings, not surfaced via the Android system locale, Intl, or any NativeModule. The SDK only offers registerLangListener (fires on UI-language change; Supernote UI languages are en / zh_CN / zh_TW / ja — no Italian) and has no getter for region or handwriting language.

Current behavior (after #28)

• The plugin follows the device language: en_US → English (correct).
• registerLangListener now handles both message shapes (string per docs, or {lang}), so runtime UI-language changes apply.
• Italian strings are kept in src/i18n/locales/it_IT.json and would show automatically only if a device's locale were Italian (e.g. it_IT).

Decision needed (later)

How should Italian (and other non-UI languages) be reachable?

• Option A — Manual language setting (Settings UI): add an in-plugin selector Auto / English / Italiano. Lets the user force Italian regardless of device.
  • ⚠️ Persistence: a durable preference needs native storage (sqlite/fs) → forces a heavyweight Android build (see SKILL gotcha ci(codeql): scan our code only (drop java-kotlin third-party noise) #33). In-memory only survives the session (resets on PluginHost/device restart), like the intro flag.
• Option B — Drop Italian auto: keep English-only auto-follow; remove/park the Italian strings.
• Option C — Heuristic on region: not currently possible — the locale is en_US, region Italy is not exposed.

References

• Fix that surfaced this: fix(i18n): follow Supernote system language (robust lang handling) #28 (robust registerLangListener + normalizeLang).
• Related: i18n setup in src/i18n/index.ts.

Parking this until we decide whether the Settings UI is worth it.