feat(machine): confirm-abandon warning, retry on error, hourglass animation

- Add confirmAbandon state UI: warns user cash can't be returned,
  offers "Show QR Code Again" or "Abandon (lose cash)"
- Error state shows "Try Again" button when bills are inserted
- Replace Skeleton loading placeholders with hourglass emoji
- Add animate-hourglass: 45-degree step rotation (Tailwind v4 @utility)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/machine/src/style.css

@@ -491,3 +491,38 @@
 @utility animate-float {
   animation: float 3s ease-in-out infinite;
 }
+
+/* Hourglass 45-degree step rotation */
+@keyframes hourglass {
+  0% {
+    transform: rotate(0deg);
+  }
+  12.5% {
+    transform: rotate(45deg);
+  }
+  25% {
+    transform: rotate(90deg);
+  }
+  37.5% {
+    transform: rotate(135deg);
+  }
+  50% {
+    transform: rotate(180deg);
+  }
+  62.5% {
+    transform: rotate(225deg);
+  }
+  75% {
+    transform: rotate(270deg);
+  }
+  87.5% {
+    transform: rotate(315deg);
+  }
+  100% {
+    transform: rotate(360deg);
+  }
+}
+
+@utility animate-hourglass {
+  animation: hourglass 4s steps(8) infinite;
+}

apps/machine/src/views/CashInView.vue

@@ -290,7 +290,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice || atmStore.isReque
           class="w-full max-w-80 border-0 bg-white/5"
         >
           <CardContent class="flex flex-col items-center gap-4 p-8">
-            <Skeleton class="h-10 w-10 rounded-full" />
+            <span class="animate-hourglass text-5xl">⏳</span>
             <p class="text-muted-foreground">Preparing payment code...</p>
           </CardContent>
         </Card>
@@ -485,7 +485,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice || atmStore.isReque
           class="w-full max-w-80 border-0 bg-white/5"
         >
           <CardContent class="flex flex-col items-center gap-4 p-8">
-            <Skeleton class="h-10 w-10 rounded-full" />
+            <span class="animate-hourglass text-5xl">⏳</span>
             <p class="text-muted-foreground">Sending receipt...</p>
           </CardContent>
         </Card>
@@ -506,12 +506,44 @@ const isProcessing = computed(() => atmStore.isPayingInvoice || atmStore.isReque
           </CardContent>
         </Card>
 
+        <!-- Confirm Abandon Warning -->
+        <Card
+          v-else-if="nestedState === 'confirmAbandon'"
+          class="w-full max-w-80 border-0 bg-red-900/30"
+        >
+          <CardContent class="flex flex-col items-center gap-4 p-8 text-center">
+            <div class="text-6xl">⚠️</div>
+            <CardTitle class="text-red-400">Cash Already Accepted</CardTitle>
+            <p class="text-muted-foreground">
+              Your {{ atmStore.fiatSymbol
+              }}{{ context ? (context.fiatAmount / 100).toLocaleString() : '' }} has been accepted
+              and cannot be returned. Please scan the QR code to receive your Bitcoin.
+            </p>
+            <Button
+              class="w-full bg-gradient-to-r from-green-500 to-emerald-400 text-black"
+              @click="atmStore.send({ type: 'RETRY' })"
+            >
+              Show QR Code Again
+            </Button>
+            <Button variant="ghost" class="w-full text-red-400" @click="cancel">
+              Abandon (lose cash)
+            </Button>
+          </CardContent>
+        </Card>
+
         <!-- Error -->
         <Card v-else-if="nestedState === 'error'" class="w-full max-w-80 border-0 bg-red-900/30">
           <CardContent class="flex flex-col items-center gap-4 p-8 text-center">
             <div class="text-6xl">⚠️</div>
             <CardTitle class="text-red-400">Error</CardTitle>
             <p class="text-muted-foreground">{{ context?.error || 'An error occurred' }}</p>
+            <Button
+              v-if="context && context.billsInserted.length > 0"
+              class="w-full bg-gradient-to-r from-green-500 to-emerald-400 text-black"
+              @click="atmStore.send({ type: 'RETRY' })"
+            >
+              Try Again
+            </Button>
             <Button
               class="bg-gradient-to-r from-orange-500 to-yellow-400 text-black"
               @click="cancel"