Bilingual blog support is now complete

The public blog now ships full English and Spanish localization, end-to-end. Every reader-facing string flows through the i18n system; nothing is hardcoded anymore.

We also trimmed the locale set down from an over-ambitious eight to a focused two: English and Spanish. The smaller set is faster to maintain and reflects where our actual readership is. Adding new locales later is now a focused, repeatable task instead of a sprawling translation backlog.

If you've been waiting to publish in two languages, the foundation is now solid in both the admin and the public blog.