feat(home): full-size frame card; horizontal carousel for multi-frame setups

Reverts the 240px preview cap — frames render at their natural device aspect
again. Single-frame layout unchanged.

For multi-frame setups, replaces the compact stack with a horizontal
scroll-snap carousel: one large card per slide, full-bleed to the viewport
edges, with dot navigation below that tracks the active slide and supports
tap-to-jump. Native CSS scroll-snap drives the swipe gesture; no extra JS
gesture library.

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

frontend/src/views/HomeView.vue

@@ -37,23 +37,51 @@
       />
     </div>
 
-    <!-- Multiple devices — compact stack -->
-    <div v-else class="home-view__list">
-      <FrameCard
-        v-for="device in devicesStore.devices"
-        :key="device.id"
-        :deviceId="device.id"
-        :name="device.name"
-        size="compact"
-        :status="deviceStatus(device)"
-        :orientation="device.orientation"
-        :thumbnailUrl="previewUrl(device)"
-        :lastSync="lastSyncLabel(device)"
-        :nextSync="nextSyncLabel(device)"
-        @add-photo="onAddPhoto"
-        @edit="onEdit"
-      />
-    </div>
+    <!-- Multiple devices — swipeable carousel of large cards -->
+    <template v-else>
+      <div
+        ref="carouselEl"
+        class="home-view__carousel"
+        role="region"
+        aria-roledescription="carousel"
+        aria-label="Frames"
+        @scroll.passive="onCarouselScroll"
+      >
+        <div
+          v-for="device in devicesStore.devices"
+          :key="device.id"
+          class="home-view__slide"
+          role="group"
+          :aria-roledescription="`Slide`"
+          :aria-label="device.name"
+        >
+          <FrameCard
+            :deviceId="device.id"
+            :name="device.name"
+            size="large"
+            :status="deviceStatus(device)"
+            :orientation="device.orientation"
+            :thumbnailUrl="previewUrl(device)"
+            :lastSync="lastSyncLabel(device)"
+            :nextSync="nextSyncLabel(device)"
+            @add-photo="onAddPhoto"
+            @edit="onEdit"
+          />
+        </div>
+      </div>
+      <div class="home-view__dots" role="tablist" aria-label="Frame selector">
+        <button
+          v-for="(d, i) in devicesStore.devices"
+          :key="d.id"
+          type="button"
+          role="tab"
+          :class="['home-view__dot', { 'home-view__dot--active': i === activeSlide }]"
+          :aria-label="`Go to ${d.name}`"
+          :aria-selected="i === activeSlide"
+          @click="goToSlide(i)"
+        />
+      </div>
+    </template>
   </main>
 
   <!-- Frame settings sheet -->
@@ -103,7 +131,7 @@
 </template>
 
 <script setup lang="ts">
-import { onMounted, ref } from 'vue'
+import { onMounted, ref, nextTick } from 'vue'
 import { useRouter } from 'vue-router'
 import { useDevicesStore } from '@/stores/devices'
 import { useUploadStore } from '@/stores/upload'
@@ -181,6 +209,25 @@ onMounted(() => {
   devicesStore.fetchDevices()
 })
 
+// ── Multi-device carousel ─────────────────────────────────────────────────────
+
+const carouselEl  = ref<HTMLElement | null>(null)
+const activeSlide = ref(0)
+
+function onCarouselScroll() {
+  const el = carouselEl.value
+  if (!el) return
+  // Each slide is 100% of the carousel width — stride is clientWidth.
+  activeSlide.value = Math.round(el.scrollLeft / el.clientWidth)
+}
+
+async function goToSlide(i: number) {
+  await nextTick()
+  const el = carouselEl.value
+  if (!el) return
+  el.scrollTo({ left: i * el.clientWidth, behavior: 'smooth' })
+}
+
 function onAddPhoto(deviceId: number) {
   // File picker must be triggered in the user-gesture context (the click handler)
   // before navigating, otherwise browsers block it as a popup.
@@ -354,10 +401,51 @@ async function saveSettings() {
     flex-direction: column;
   }
 
-  &__list {
+  // Carousel: full-bleed horizontal scroll-snap. The container ignores the
+  // page's side padding so cards reach edge-to-edge; each slide pads itself
+  // back in so the card visually aligns with the rest of the page.
+  &__carousel {
     display: flex;
-    flex-direction: column;
+    overflow-x: auto;
+    overflow-y: hidden;
+    scroll-snap-type: x mandatory;
+    scroll-behavior: smooth;
+    scrollbar-width: none;
+    -webkit-overflow-scrolling: touch;
+    margin: 0 calc(-1 * var(--space-4));
+
+    &::-webkit-scrollbar { display: none; }
+  }
+
+  &__slide {
+    flex: 0 0 100%;
+    box-sizing: border-box;
+    padding: 0 var(--space-4);
+    scroll-snap-align: start;
+    scroll-snap-stop: always;
+  }
+
+  &__dots {
+    display: flex;
+    justify-content: center;
     gap: var(--space-2);
+    padding-top: var(--space-3);
+  }
+
+  &__dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 50%;
+    border: none;
+    padding: 0;
+    background: var(--color-border);
+    cursor: pointer;
+    transition: background var(--duration-fast), transform var(--duration-fast);
+
+    &--active {
+      background: var(--color-primary);
+      transform: scale(1.25);
+    }
   }
 
   &__sheet-title {