printedparts stage 8: 1x0.5in bin labels

New public print view at /print/printedparts-labels following the
plugin-owned USB label precedent: multi-select with per-item copies,
CODE128 of the item code via JsBarcode (a QR at this size is at the
edge of scanner tolerance), one label per page on 1in x 0.5in roll
stock via a new @page size. The Detail page's Bin Label button
preselects its item through ?item=<id>; the list header gains a batch
Print Labels button.

frontend/src/router/index.js

@@ -117,6 +117,12 @@ const routes = [
     component: () => import('../views/print/USBLabelBatch.vue'),
     meta: { plugin: 'usb' }
   },
+  {
+    path: '/print/printedparts-labels',
+    name: 'print-printedparts-labels',
+    component: () => import('../views/print/PrintedPartsLabels.vue'),
+    meta: { plugin: 'printedparts' }
+  },
   {
     path: '/',
     component: AppLayout,

frontend/src/views/print/PrintedPartsLabels.vue

@@ -0,0 +1,207 @@
+<template>
+  <div>
+    <div class="no-print">
+      <div class="controls">
+        <h3>Print 3D Parts Bin Labels (1in x 0.5in)</h3>
+        <p>
+          Each label is one page on 1in x 0.5in roll stock: CODE128 barcode of
+          the item code, scannable at the parts kiosk.
+        </p>
+
+        <div v-if="loading" class="loading-msg">Loading parts...</div>
+        <div v-else-if="items.length === 0" class="loading-msg">No parts found</div>
+        <div v-else class="parts-grid">
+          <div
+            v-for="item in items"
+            :key="item.printeditemid"
+            class="part-item"
+            :class="{ selected: isSelected(item) }"
+            @click="toggleItem(item)"
+          >
+            <input type="checkbox" :checked="isSelected(item)" @click.stop />
+            <label>
+              <strong><code>{{ item.itemcode }}</code></strong>
+              <div class="alias">{{ item.itemname }}</div>
+            </label>
+          </div>
+        </div>
+
+        <div class="selected-count">
+          Selected: <span class="count">{{ selectedItems.length }}</span> labels
+          <label class="copies-label">Copies each:
+            <input v-model.number="copies" type="number" min="1" max="10" />
+          </label>
+        </div>
+
+        <button class="print-btn" :disabled="selectedItems.length === 0"
+                @click="print">Print Labels</button>
+        <button class="clear-btn" @click="selectedItems = []">Clear All</button>
+        <button class="select-all-btn" @click="selectedItems = [...items]">Select All</button>
+      </div>
+    </div>
+
+    <div class="labels-container">
+      <div v-for="(label, index) in printLabels" :key="index" class="bin-label">
+        <svg :ref="element => setBarcodeElement(element, index)" class="bin-barcode"></svg>
+        <div class="bin-code">{{ label.itemcode }}</div>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref, computed, onMounted, watch, nextTick } from 'vue'
+import JsBarcode from 'jsbarcode'
+import { printedpartsApi } from '../../api'
+
+const items = ref([])
+const selectedItems = ref([])
+const copies = ref(1)
+const loading = ref(true)
+const barcodeElements = ref({})
+
+onMounted(async () => {
+  try {
+    const response = await printedpartsApi.list({ perpage: 500 })
+    items.value = response.data.data || []
+    // ?item=<id> preselects one part (the Detail-page print button)
+    const preselect = new URLSearchParams(window.location.search).get('item')
+    if (preselect) {
+      const match = items.value.find(
+        candidate => String(candidate.printeditemid) === preselect)
+      if (match) selectedItems.value = [match]
+    }
+  } catch (error) {
+    console.error('Error loading parts:', error)
+  } finally {
+    loading.value = false
+  }
+})
+
+const printLabels = computed(() => {
+  const labels = []
+  for (const item of selectedItems.value) {
+    for (let copy = 0; copy < Math.max(1, copies.value); copy++) {
+      labels.push(item)
+    }
+  }
+  return labels
+})
+
+function isSelected(item) {
+  return selectedItems.value.some(
+    candidate => candidate.printeditemid === item.printeditemid)
+}
+
+function toggleItem(item) {
+  if (isSelected(item)) {
+    selectedItems.value = selectedItems.value.filter(
+      candidate => candidate.printeditemid !== item.printeditemid)
+  } else {
+    selectedItems.value = [...selectedItems.value, item]
+  }
+}
+
+function setBarcodeElement(element, index) {
+  if (element) barcodeElements.value[index] = element
+}
+
+watch(printLabels, async labels => {
+  await nextTick()
+  labels.forEach((label, index) => {
+    const element = barcodeElements.value[index]
+    if (element) {
+      // CODE128 of the short item code fits 1x0.5in with comfortable
+      // scanner tolerance; a QR at this size would be marginal.
+      JsBarcode(element, label.itemcode, {
+        format: 'CODE128',
+        displayValue: false,
+        width: 1.4,
+        height: 26,
+        margin: 0
+      })
+    }
+  })
+}, { deep: true })
+
+function print() {
+  window.print()
+}
+</script>
+
+<style scoped>
+.controls {
+  max-width: 46rem;
+  margin: 1rem auto;
+  padding: 1rem;
+  background: var(--bg-card);
+  border: 1px solid var(--border);
+  border-radius: 0.5rem;
+}
+.parts-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(14rem, 1fr));
+  gap: 0.5rem;
+  max-height: 20rem;
+  overflow-y: auto;
+  margin: 1rem 0;
+}
+.part-item {
+  display: flex;
+  gap: 0.5rem;
+  padding: 0.5rem;
+  border: 1px solid var(--border);
+  border-radius: 0.35rem;
+  cursor: pointer;
+}
+.part-item.selected { border-color: var(--primary); }
+.alias { color: var(--text-light); font-size: 0.85rem; }
+.selected-count { margin: 0.75rem 0; }
+.copies-label { margin-left: 1.25rem; }
+.copies-label input { width: 4rem; padding: 0.25rem; }
+.print-btn, .clear-btn, .select-all-btn {
+  margin-right: 0.5rem;
+  padding: 0.5rem 1rem;
+  cursor: pointer;
+}
+.loading-msg { color: var(--text-light); padding: 1rem; }
+
+/* screen preview of the labels */
+.labels-container { display: flex; flex-wrap: wrap; gap: 0.4rem; padding: 1rem; }
+.bin-label {
+  width: 1in;
+  height: 0.5in;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+  background: #fff;
+  outline: 1px dashed #bbb;
+}
+.bin-barcode { width: 0.92in; height: 0.3in; }
+.bin-code {
+  font-size: 6.5pt;
+  font-family: monospace;
+  color: #000;
+  line-height: 1;
+}
+
+/* 1in x 0.5in roll stock: one label per page */
+@media print {
+  .no-print { display: none; }
+  .labels-container { display: block; padding: 0; gap: 0; }
+  .bin-label {
+    outline: none;
+    page-break-after: always;
+    break-after: page;
+  }
+}
+</style>
+
+<style>
+@media print {
+  @page { size: 1in 0.5in; margin: 0; }
+  body { margin: 0; }
+}
+</style>

frontend/src/views/printedparts/PrintedItemDetail.vue

@@ -27,6 +27,8 @@
             </button>
             <router-link :to="`/printedparts/${item.printeditemid}/edit`"
                          class="btn btn-secondary btn-sm">Edit</router-link>
+            <router-link :to="`/print/printedparts-labels?item=${item.printeditemid}`"
+                         class="btn btn-secondary btn-sm">Bin Label</router-link>
           </div>
         </div>
       </div>

frontend/src/views/printedparts/PrintedItemsList.vue

@@ -2,7 +2,12 @@
   <div>
     <div class="page-header">
       <h2>3D Printed Parts</h2>
-      <router-link to="/printedparts/new" class="btn btn-primary">Add Part</router-link>
+      <div class="header-actions">
+        <router-link to="/print/printedparts-labels" class="btn btn-secondary">
+          Print Labels
+        </router-link>
+        <router-link to="/printedparts/new" class="btn btn-primary">Add Part</router-link>
+      </div>
     </div>
 
     <div class="filters">
@@ -131,6 +136,7 @@ function debouncedSearch() {
   text-overflow: ellipsis;
   white-space: nowrap;
 }
+.header-actions { display: flex; gap: 0.5rem; }
 .lowstock-filter {
   display: inline-flex;
   align-items: center;