feat(ui): Terminal tab — embedded blackflame ttyd to CT300 (claude in persistent tmux)

ttyd on CT300 (:7681, firewalled to Traefik) behind same-origin /terminal via
Traefik + CF Access; iframe view + nav entry.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/router.js

@@ -23,6 +23,7 @@ const ROUTES = [
   { name: 'sacred-valley', re: /^\/sacred-valley$/, keys: [] },
   { name: 'sentinel', re: /^\/sentinel$/, keys: [] },
   { name: 'little-blue', re: /^\/little-blue$/, keys: [] },
+  { name: 'terminal', re: /^\/terminal$/, keys: [] },
   { name: 'jobs', re: /^\/jobs$/, keys: [] },
   { name: 'home',     re: /^\/?$/,                 keys: [] }
 ];