Authored (Studio) translations never reach the i18n runtime — only static bundles are loaded #2591

Summary

A translation authored in the Studio (saved as translation metadata) is never loaded into the i18n runtime — not served on publish, and not after a restart. The i18n service only ever loads static bundles (compiled bundle.translations + each plugin's own translations/). translation is flagged allowRuntimeCreate: true but nothing consumes runtime-authored translation items. Declared-but-not-wired, not a stale-cache bug.

Found in the post-#2576 boot-cached-consumer audit.

Evidence

• packages/services/service-i18n serves GET /api/v1/i18n/translations/:locale straight from an in-memory Map in FileI18nAdapter (file-i18n-adapter.ts — translations map, getTranslations).
• That map is populated only via loadTranslations(locale, data), and every caller passes a static bundle: packages/runtime/src/app-plugin.ts:819 (bundle.translations) and each plugin's bundled strings (plugin-audit, plugin-security, plugin-sharing, plugin-approvals, plugin-webhooks, platform-objects — all i18n.loadTranslations(locale, <bundled data>)).
• No code reads translation metadata (getMetaItems({type:'translation'}) / metadata.list('translation') / sys_metadata) into the i18n service. On the showcase, GET /api/v1/meta/translation returns 0 items even though translations render (they come from the compiled bundle).
• Net: authoring + publishing a translation in the Studio has no runtime effect whatsoever.

Impact

priority:p2 (cosmetic — labels/strings, not correctness). But it's a complete dead-end for a first-class authorable type, and undermines the localization-authoring story.

Proposed fix

1. Load translation metadata into service-i18n at boot from the protocol (protocol.getMetaItems({ type: 'translation' })), mapping each item to loadTranslations(locale, data). Requires deciding the translation-item → { [locale]: TranslationData } shape/merge order vs the static bundle (overlay-on-top).
2. Subscribe to metadata:reloaded (fired on publish since fix(automation): bind a flow published while the server runs, without a restart #2576) to re-sync — with a clear-then-reload for the authored subset (removed keys must not linger; loadTranslations currently deep-merges, so deletions need explicit handling).

Bigger than a subscription — needs the boot-load wiring + a mapping/merge design. Companion to the hooks (#2588) and sharing runtime-authoring gaps.