Complete the Brazilian Portuguese (pt-BR) localization

[OCampezzi]

Summary

This PR completes the Brazilian Portuguese (pt-BR) localization and fixes several existing translations.

I went through both string catalogs, translated all remaining strings, and reviewed the existing ones for accuracy and consistency.

What changed

• Fixed translations that had incorrect or misleading meanings, such as "Enable Rectangle.app" and "Snap Areas".
• Updated macOS terminology to match Apple's Brazilian Portuguese conventions (e.g. "Ajustes do Sistema", "Privacidade e Segurança", "Organizador Visual").
• Made window position names consistent across halves, corners, and grids.
• Translated around 190 missing strings, including eighths, ninths, twelfths, sixteenths, stacked windows, mouse shortcuts, and other settings.
• Fixed strings that were still in English despite being marked as translated.
• Added the missing catalog entry for "Snap before reaching screen edges", so it can now be translated into other languages too.

Note

"Left" and "Right" use the same translation keys for both window positioning and the Todo sidebar. Since they can't be translated separately, I went with "Esquerda" and "Direita", which work in both contexts.

[rxhanson]

Thanks! I appreciate the note on left & right. I'll have to disambiguate that.