printedparts stage 4: catalog mutations, item photos, detail + form

POST/PUT/DELETE for items: create mints the itemcode from the
configured prefix plus the flushed row id, update refuses
quantityonhand (ledger-managed - restock/adjust arrive next stage),
delete soft-retires. The image upload/serve/delete trio replicates the
models.py pattern into instance/printedpartsimages/ with a public GET.
PrintedItemDetail follows the unified detail skeleton (hero photo,
info list, transaction history table); PrintedItemForm covers
create/edit plus photo management on edit.

frontend/src/api/index.js

@@ -1134,5 +1134,24 @@ export const printedpartsApi = {
   },
   get(printeditemid) {
     return api.get(`/printedparts/items/${printeditemid}`)
+  },
+  create(data) {
+    return api.post('/printedparts/items', data)
+  },
+  update(printeditemid, data) {
+    return api.put(`/printedparts/items/${printeditemid}`, data)
+  },
+  remove(printeditemid) {
+    return api.delete(`/printedparts/items/${printeditemid}`)
+  },
+  uploadImage(printeditemid, file) {
+    const formData = new FormData()
+    formData.append('file', file)
+    return api.post(`/printedparts/items/${printeditemid}/image`, formData, {
+      headers: { 'Content-Type': 'multipart/form-data' }
+    })
+  },
+  deleteImage(printeditemid) {
+    return api.delete(`/printedparts/items/${printeditemid}/image`)
   }
 }