design: atmospheric redesign mockups (login + SPA, six dusks)

Self-contained HTML/CSS mockups proposing the brand-as-surface direction:
- Camogli harbor photo as the permanent backdrop on every authenticated view
- Six user themes rebuilt as atmospheric "dusks" (tinted overlays + accents)
  instead of cream variants
- Frosted-glass cards on top of the photo
- Same type system (Marcellus / Cormorant Garamond italic / Nunito body)
  shared between login and in-app

Includes:
- login-cinematic.html: canonical pre-auth example with Ken-Burns + grain
- spa/home.html, library.html, settings.html: in-app views with the new chrome
- spa/_tokens.css + _chrome.css: dusk system and frosted-glass primitives
- favicons/A-D: in-progress icon directions
- README.md with serving instructions and the porting checklist

Saved as a durable design artifact so the iteration survives /tmp wipes
and can be referred back to when porting to Vue.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

_design/atmospheric-redesign/favicons/B-frame-horizon.svg

@@ -0,0 +1,12 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
+  <rect width="64" height="64" rx="10" fill="#1a3a5c"/>
+  <!-- inner frame -->
+  <rect x="10" y="10" width="44" height="44" rx="3" fill="#fdf6ee"/>
+  <rect x="13" y="13" width="38" height="38" fill="#cfe2ea"/>
+  <!-- sea -->
+  <rect x="13" y="35" width="38" height="16" fill="#4a7a9a"/>
+  <!-- sun -->
+  <circle cx="32" cy="32" r="9" fill="#f0d000"/>
+  <!-- frame matt highlights -->
+  <rect x="10" y="10" width="44" height="44" rx="3" fill="none" stroke="#0e2640" stroke-width="0.8" opacity="0.6"/>
+</svg>