Update translations for all new and changed strings

[howarddc]

Summary

• Regenerated languages/everyalt.pot from source: 163 strings (113 new since 1.0.2, 12 removed — including the intro-notice string, whose translations were already stale).
• Translated every new string for all 7 bundled locales: de_DE, es_ES, fr_FR, it_IT, ja, nl_NL, pt_BR — each now 163/163, 0 fuzzy. Existing translations untouched.
• Fixed es_ES Plural-Forms (nplurals=1 → nplurals=2; plural=(n != 1)); Spanish has singular/plural forms.
• Recompiled all .mo files.

Conventions

• Reused each file's existing terminology and formality (e.g. German "du", French "vous", Japanese です/ます).
• EveryAlt's own tab/setting names are translated once and reused wherever the text refers to them.
• Product, model, and standard names (EveryAlt, OpenAI, Gemini, DeepInfra, WCAG, WP-Cron, …) kept as is; third-party dashboard button labels (“Create new secret key”, etc.) kept in English since those dashboards may not be localized.

Verification

• msgfmt --check --check-format --statistics clean for every locale
• Independent check: placeholders, HTML tags, and product names preserved in every string; no existing translation changed; no string left identical to English (except the intentional loanword "Trust center" in it_IT)

Worth a native speaker's review

Free/paid "tier", "authoritative" (provider invoice), and "zero data retention" were rendered idiomatically rather than literally in several languages.

🤖 Generated with Claude Code