[Jairolaya12x]

Summary

Adds a Spanish (Latin America) translation and makes every language code follow the same language_REGION format.

Spanish translation

• New assets/i18n/es_419.json catalog covering every message in the English source.
• Fixed entries that had been left in English, mostly ones containing "Y" (e.g. "Y axis" → "Eje Y", "Flip Y" → "Voltear Y", "Board Y" → "Tabla Y"), as well as "Hectares" → "Hectáreas".
• Spanish appears in the language picker and is detected from browser/OS locales (es, es-ES, es-MX, es-419, …).

Consistent language codes

• en → en_US and es → es_419, matching the existing zh_CN and pt_BR.
• Renamed the catalogs to en_US.json and es_419.json, and updated build.rs, the web startup loader in index.html, the web test scripts and AGENTS.md.
• Saved preferences that still contain en or es are converted to the new codes automatically, so no one loses their selected language.
• Locale detection now falls back by primary language for every catalog (previously only Portuguese did this), while Traditional Chinese still never maps to zh_CN.

Language picker

• Renamed the keys settings.language_* → settings.language.*.
• Translated catalogs show each language by its native name (English, 简体中文, Português (Brasil), Español), matching the existing zh_CN and pt_BR catalogs.
• Added "Español" to the zh_CN and pt_BR catalogs, which previously showed "Spanish".

Tests

• Added Spanish cases alongside the existing pt_BR ones: label, format and plural switching, settings window, View menu, export dialog and presets, first-launch language persistence, 3D Mouse status, and history labels.
• New tests:
  • supported_languages_include_spanish
  • language_picker_shows_native_names_in_translated_catalogs
  • every_language_code_uses_language_and_region
  • saved_bare_language_codes_migrate_to_regional_codes
  • Spanish locale detection

[Jairolaya12x]

Hey @dannycoulombe, do you think we could rename these keys to follow the settings.language.<option-here> convention?

"settings.language_simplified_chinese": "Chino simplificado",
"settings.language_brazilian_portuguese": "Portugués brasileño",
"settings.language_spanish": "Español",

This would make it easier to validate and manage the available language options consistently.

WDYT?

[dannycoulombe]

That makes perfect sense to me! Yes.

[Jairolaya12x]

Hey @dannycoulombe I added some changes on the structure of the i18n files, please let me know if this is ok, because I think that can affect the next PRs

[dannycoulombe]

Good catch for the language code. I agree.

[dannycoulombe]

• Translated catalogs show each language by its native name (English, 简体中文, Português (Brasil), Español), matching the existing zh_CN and pt_BR catalogs.

100%

[dannycoulombe]

Te agradezco mucho por este commit! Saludos desde Mexico!