feat(auth): redesign Login and Setup pages with split-panel branding layout (#168)

* feat(auth): redesign Login and Setup pages with split-panel branding layout

Replace plain Card-based Login and Setup forms with a professional
split-panel layout: always-dark branding panel (dot grid texture, logo,
tagline, cyan accent line) on the left, theme-aware form on the right.
Mobile collapses to single column with compact logo header.

- Add optional admin email field on Setup for license recovery
- Backend accepts and stores admin_email in setup endpoint
- Fix data-stacks-loaded attribute forwarding (wrap in div, use string values)

* docs: add license-settings and profile-dropdown screenshots

* fix(docs): correct logo paths from .svg to .png

* fix(deps): resolve picomatch high-severity vulnerability

docs/docs.json

@@ -8,8 +8,8 @@
     "dark": "#0F172A"
   },
   "logo": {
-    "light": "/images/logo/logo-light.svg",
-    "dark": "/images/logo/logo-dark.svg",
+    "light": "/images/logo/logo-light.png",
+    "dark": "/images/logo/logo-dark.png",
     "href": "/"
   },
   "favicon": "/images/logo/favicon.ico",