FX.141 Apps: every app page decoded 130 language files (43 MB) to list the languages in Settings

Built: app-settings.inc called json_decode on every language file under assets/lang on every /use and /lab app page to show each language's own name in Settings, 156 ms of PHP per page view. Lang::nameOf() now reads the first 1 KB of a file and takes "@name" from it (every file tools/lang writes puts @locale and @name first; a head without it falls back to a full decode). app-settings.inc and Lang::siteChoices use it. Measured: app-settings.inc 156 ms to 2 ms, time to first byte of /use/cadcraft on localhost 230 to 290 ms to 95 to 110 ms, the same 84 language options. Tests bin/test-lang-packs.php 21/21. Log docs/0.9-sessions/perf-09.md. (Filed as FX.137 in that log at first; the key was taken by the arc methods the same day, so this row is FX.141.)