v0.1.0-rc.3

The site now ships in eight languages, not just the tool: 32 real
documents translated at build time, with hreflang, per-locale canonicals
and a sitemap that lists all of them. Plus /styles, the preset gallery
rendered from the engine's own numbers.

Also in this build: VAD before the recogniser so a silent clip produces
no subtitles, inline-echo trimming, flicker merging in the Rust cue
segmenter, and language-label smoothing.