The landing Playwright suite ran in no CI workflow, so six specs had drifted red on main. Five subpages navigation tests asserted bare paths while the site emits trailing-slash URLs (format: directory), and one asserted a localized tool-detail page that is English-only by design. Fix the assertions and rewrite the tool test to the real invariant, then add a test-e2e-landing job gated on a new landing path filter so the suite runs on landing-relevant PRs and can't silently rot again.
Shared Claude Code translation pipeline (scripts/i18n, no API key) plus Astro/VitePress/Scalar i18n wiring. Landing and API reference translated into all 20 languages; docs i18n wiring + English source anchors. The translated docs markdown (apps/docs/<locale>/**, 3,620 files) follows in a companion PR because it exceeds GitHub's per-PR CI file limit.
