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/components/sidebar.js

@@ -93,6 +93,7 @@ export function renderSidebar(root) {
       navItem('Sacred Valley', '/sacred-valley'),
       navItem('Sentinel', '/sentinel'),
       navItem('Little Blue', '/little-blue'),
+      navItem('Terminal', '/terminal'),
       navItem('Search', '/search'),
       inboxItem,
       navItem('Jobs', '/jobs'),