printedparts stage 7: the kiosk - scan bin, scan badge, keypad, take

Two open endpoints: an item lookup by scanned code and the take POST -
the product's first unauthenticated write, held to the decision
record's bar (decrement-only, badge-attributed server-side, bounded,
physically rate-limited; justification in the plugin README). The
/parts-kiosk route is a full-screen no-auth view beside /shopfloor: a
hidden always-focused input consumes keyboard-wedge scans for
whichever step is active, TouchKeypad (net-new 3x4 grid) takes the
quantity, and a success screen resets after a few seconds. Manual
type-in fallbacks cover damaged labels. Kiosk test proves open access,
the over-take guard, the badge policy, and cache==ledger afterward.

frontend/src/components/TouchKeypad.vue

@@ -0,0 +1,38 @@
+<template>
+  <div class="touch-keypad">
+    <button v-for="digit in digits" :key="digit" type="button"
+            class="keypad-button" @click="$emit('digit', digit)">
+      {{ digit }}
+    </button>
+    <button type="button" class="keypad-button keypad-muted"
+            @click="$emit('clear')">C</button>
+    <button type="button" class="keypad-button" @click="$emit('digit', '0')">0</button>
+    <button type="button" class="keypad-button keypad-muted"
+            @click="$emit('backspace')">&lt;</button>
+  </div>
+</template>
+
+<script setup>
+const digits = ['1', '2', '3', '4', '5', '6', '7', '8', '9']
+defineEmits(['digit', 'clear', 'backspace'])
+</script>
+
+<style scoped>
+.touch-keypad {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 0.6rem;
+  max-width: 20rem;
+}
+.keypad-button {
+  font-size: 1.8rem;
+  padding: 1rem 0;
+  border-radius: 0.5rem;
+  border: 1px solid var(--border);
+  background: var(--bg-card);
+  color: var(--text);
+  cursor: pointer;
+}
+.keypad-button:active { background: var(--primary); color: #fff; }
+.keypad-muted { color: var(--text-light); }
+</style>