fix(design-v2): side rail subtitle + footer signature + theme swatch harbor

Mockup vs live diff revealed:
- Side rail brand area: mockup has italic '— home/library/settings' subtitle
  below WeVisto, live had none. Added via reactive activeSub computed.
- Side rail footer: mockup has 'a frame, gifted · v 0.4' italic at the
  bottom of the rail. Added top-nav__foot element; hidden in horizontal
  layouts, shown in v2 side rail via design-v2.scss
- Side rail mark size: bumped from 36px to 44px to match mockup
- Theme swatch harbor preview wasn't winning the cascade fight against
  Vue scoped styles (equal-specificity tie, Vue cascades later). Adding
  !important on the few preview properties — v2 is opt-in so this is
  appropriate.

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

frontend/src/components/TopNav.vue

@@ -2,7 +2,10 @@
   <header class="top-nav" aria-label="Main navigation">
     <RouterLink to="/" class="top-nav__brand">
       <span class="top-nav__mark"><img :src="markUrl" alt=""></span>
-      <span class="top-nav__wordmark">WeVisto</span>
+      <span class="top-nav__title-group">
+        <span class="top-nav__wordmark">WeVisto</span>
+        <span class="top-nav__sub">— {{ activeSub }}</span>
+      </span>
     </RouterLink>
     <nav class="top-nav__tabs">
       <RouterLink
@@ -20,6 +23,7 @@
         >{{ imagesStore.pendingCount > 9 ? '9+' : imagesStore.pendingCount }}</span>
       </RouterLink>
     </nav>
+    <div class="top-nav__foot">a frame, gifted <span class="top-nav__foot-sep">·</span> v 0.4</div>
   </header>
 </template>
 
@@ -27,10 +31,22 @@
 import { useRoute, type RouteLocationNormalizedLoaded } from 'vue-router'
 import { useImagesStore } from '@/stores/images'
 
+import { computed } from 'vue'
+
 const route       = useRoute()
 const imagesStore = useImagesStore()
 const markUrl     = '/build/icons/apple-touch-icon.png'
 
+// "— home" / "— library" / "— settings" subtitle on the brand area.
+// Matches the approved mockup; hidden at mobile/tablet via CSS.
+const activeSub = computed(() => {
+  const p = route.path
+  if (p.startsWith('/library')) return 'library'
+  if (p.startsWith('/settings')) return 'settings'
+  if (p.startsWith('/upload')) return 'add photograph'
+  return 'home'
+})
+
 interface Tab {
   name: string
   label: string
@@ -96,6 +112,12 @@ const tabs: Tab[] = [
   }
   &__mark img { width: 100%; height: 100%; display: block; }
 
+  &__title-group {
+    display: flex;
+    flex-direction: column;
+    line-height: 1.1;
+  }
+
   &__wordmark {
     font-size: var(--text-lg);
     font-weight: 800;
@@ -103,6 +125,29 @@ const tabs: Tab[] = [
     color: var(--color-text);
   }
 
+  // Italic subtitle "— home / library / settings" beside the wordmark.
+  // Hidden at horizontal (mobile/tablet) layouts; v2 side rail shows it.
+  &__sub {
+    display: none;
+    font-size: 12px;
+    color: var(--color-text-muted);
+    margin-top: 2px;
+    font-style: italic;
+  }
+
+  // Bottom-of-rail signature — only renders inside the side-rail layout
+  // (positioned absolutely there). Hidden in the horizontal default state.
+  &__foot {
+    display: none;
+    font-size: 12px;
+    font-style: italic;
+    color: var(--color-text-muted);
+    text-align: center;
+    padding: 16px 0 4px;
+    border-top: 1px solid var(--color-border);
+  }
+  &__foot-sep { color: var(--brand-yellow, var(--color-primary)); }
+
   &__tabs {
     display: flex;
     gap: var(--space-1);

frontend/src/styles/design-v2.scss

@@ -39,8 +39,26 @@
         padding-bottom: 20px;
         margin-bottom: 16px;
         border-bottom: 1px solid var(--color-border);
+        align-items: flex-start;
+      }
+      &__mark {
+        width: 44px !important;
+        height: 44px !important;
+        border-radius: 10px !important;
+      }
+      &__wordmark { font-size: var(--text-xl); font-family: var(--font-display-v2); font-weight: 400; }
+
+      &__sub {
+        display: block;
+        font-family: var(--font-accent-v2);
+      }
+
+      &__foot {
+        display: block;
+        margin-top: auto;
+        font-family: var(--font-accent-v2);
+        border-top-color: var(--color-border);
       }
-      &__wordmark { font-size: var(--text-xl); }
 
       &__tabs {
         flex-direction: column;
@@ -124,18 +142,22 @@
   .design-toggle__sub { color: var(--color-text-muted); }
 
   // ── Theme swatches preview their dusk via the harbor.jpg ───────────
+  // `!important` needed because Vue's scoped style on SettingsView
+  // (.theme-swatch__preview[data-v-xxx] { background: var(--swatch-bg) })
+  // ties on specificity and cascades later. v2 is opt-in so overriding is OK.
   .theme-swatch {
     border-color: var(--color-border);
-    background: var(--color-surface);
+    background: var(--color-surface) !important;
     color: var(--color-text);
 
     &--active { border-color: var(--brand-yellow); }
     &__label { color: var(--color-text); }
 
     &__preview {
-      background-image: url('/build/assets/harbor.jpg');
-      background-size: cover;
-      background-position: center;
+      background: transparent !important;
+      background-image: url('/build/assets/harbor.jpg') !important;
+      background-size: cover !important;
+      background-position: center !important;
       position: relative;
       overflow: hidden;
       &::after {