- Add integrity= + crossorigin= to all 4 cdnjs tags in admin_welcome.html
and admin_setup_banner.html (I-1)
- Add graceful CDN fallback: when CodeMirror is undefined (SRI mismatch or
CDN down), degrade to styled plain textarea with polyfill editor interface
so save/reset/preview still work (I-1)
- Replace fixed 480px editor height with calc(100vh - 320px) for
viewport-relative sizing; add min-height: 480px to .welcome-editor-col (M-8)
- Change /install redirect from 301 to 302 to prevent indefinite browser
caching (I-5)
- Sanitize Jinja2 error detail in /api/welcome 500 response: log full error
server-side, return generic detail pointing at /admin/welcome (M-7)
- Hoist build_context import to module level in app/api/welcome.py (M-11)
Adds an optional Jinja2/HTML banner displayed above the bootstrap
commands on /setup. Empty by default; admin authors it at
/admin/setup-banner. autoescape=True — safe for HTML context.
Render failures return "" so a broken banner never breaks /setup.
Schema v22: setup_banner singleton table, auto-migration v21→v22.
