[antosubash]

Summary

• The per-tab i18n catalog sync from hosting: i18n catalog marker is per-session, not per-tab — other tabs keep the old language after a locale switch #788 moved from host/client_app/i18n.ts into the published package as @simple-module-py/i18n/inertia.
  • The sync sends X-SM-I18n on every Inertia visit, adopts each non-null catalog, and reloads i18n once when the locale changes without a catalog.
  • It exports bootI18nFromInitialPage(i18n) and subscribeI18nToNavigation(router).
  • The router is passed in under a structural I18nRouter type, so the package doesn't depend on @inertiajs/react.
• This repo's host and the smpy new template app.tsx both use it. Scaffolded apps used to keep their own success handler, which sent no header and fell back to the per-session markers.
• The tests moved to packages/i18n/src/inertia.test.ts. The scaffold regression test now checks the shared wiring.
• Docs updated: the package README, docs/framework/i18n.md, docs/frontend/shared-props.md and docs/frontend/performance.md. The CHANGELOG entry tells existing apps how to switch.

Closes #871

Verification

• In a scaffolded app with the new template and package: tsc passes. A sidebar navigation sends x-sm-i18n: en:full, and the response carries "messages": null, so the tab keeps its catalog.
• Local CI: make lint ✓, make ci-docs-build ✓, make test-py ✓ (8323), make test-js ✓ (906).
• Reviewed by correctness and maintainability reviewers (docs fixes) and by Codex. Codex caught a stale scaffold test, now fixed, and its final review found nothing.
• Verification report: https://claude.ai/artifact/FhG3gugcZBtJco17bv9H1f

Report links are Claude Artifacts and start private — the author can share them
from claude.ai/code/artifacts if reviewers need access.

Test plan

• In this repo's dev host, switch locale and sign in; translations stay correct without a hard refresh
• CI is green

[chatgpt-codex-connector]

Codex Review Summary: ✅ Completed

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
🔒 Security Review	✅ Completed 2026-11-11T01:10:57.765145Z	cb45677	PR opened

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