Evidence — language toggle in the navbar (ZER0-078)

New-feature evidence (after-only — there is no "before" to revert): the multilingual language toggle added by _includes/components/language-toggle.html, captured on an English docs page that has a generated French translation. The French fixture was produced by the pipeline's offline stub provider (ruby scripts/translate.rb --provider stub --only vendor-assets), so no API credential is involved; visible [fr] markers are the stub's deterministic pseudo-translation, exercising exactly the code paths real Claude output flows through.

• 01-viewport-matrix.png — the navbar band at 320→1440px: the toggle (translate icon + EN code from xl up) sits in the utility cluster next to search/settings and never clips or overflows the page (metrics.json: overflow 0px at every width).
• 02-configs.png — toggle closed vs dropdown open at 1280px (the fixed-navbar crop truncates the open menu; see the close-up below).
• 03-dropdown-open.png — close-up of the open menu: English is the active entry (aria-current="true"), Français is a real link to /fr/docs/development/vendor-assets/ because the translation exists. On pages without a translation the entry renders disabled with a "Not yet translated" title instead — that state is pinned by test/visual/features/language-toggle.spec.js.

Regeneration steps are documented in test/visual/language-toggle-evidence.mjs.