feat(phase7.4): order rejection + resubmit flow

- Migration 053: rejection_reason TEXT NULL on orders table
- POST /api/orders/{id}/reject (PM+): sets rejected status, cancels
  active renders, stores reason, notifies creator, broadcasts WS event
- POST /api/orders/{id}/resubmit (creator or PM+): resets to draft,
  clears rejection fields, notifies PMs
- OrderDetail: Reject button (PM+) + inline modal with reason textarea
  and notify-client checkbox; Resubmit button; rejection reason amber
  alert box shown below header when order is rejected
- Orders Kanban: rejection_reason shown as red italic note on card
- Order interface: rejected_at, rejection_reason fields

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

frontend/src/pages/OrderDetail.tsx

@@ -8,9 +8,10 @@ import {
   ChevronDown, ChevronUp, ChevronsUpDown,
   Search, SlidersHorizontal, FileSpreadsheet, Box,
   Loader2, Play, RefreshCw, ExternalLink, Ban, StopCircle, Scissors, Plus, Wand2, Download,
+  XCircle, RotateCw,
 } from 'lucide-react'
 import { toast } from 'sonner'
-import { getOrder, submitOrder, deleteOrder, unlinkCadFile, regenerateItemThumbnail, patchOrderItem, removeOrderLine, dispatchRenders, cancelLineRender, cancelOrderRenders, splitMissingStep, generateLinesFromItems, downloadOrderRenders } from '../api/orders'
+import { getOrder, submitOrder, deleteOrder, unlinkCadFile, regenerateItemThumbnail, patchOrderItem, removeOrderLine, dispatchRenders, cancelLineRender, cancelOrderRenders, splitMissingStep, generateLinesFromItems, downloadOrderRenders, rejectOrder, resubmitOrder } from '../api/orders'
 import type { OrderItem, OrderLine } from '../api/orders'
 import { listOutputTypes } from '../api/outputTypes'
 import type { OutputType } from '../api/outputTypes'
@@ -60,6 +61,9 @@ export default function OrderDetailPage() {
   const [genLinesOpen, setGenLinesOpen] = useState(false)
   const [genLinesSelected, setGenLinesSelected] = useState<Record<string, boolean>>({})
   const [isDownloading, setIsDownloading] = useState(false)
+  const [rejectModalOpen, setRejectModalOpen] = useState(false)
+  const [rejectReason, setRejectReason] = useState('')
+  const [rejectNotifyClient, setRejectNotifyClient] = useState(true)
 
   // Table state
   const [filters, setFilters] = useState<TableFilters>(EMPTY_FILTERS)
@@ -148,6 +152,28 @@ export default function OrderDetailPage() {
     onError: (e: any) => toast.error(e.response?.data?.detail || 'Split failed'),
   })
 
+  const rejectMut = useMutation({
+    mutationFn: () => rejectOrder(id!, rejectReason, rejectNotifyClient),
+    onSuccess: () => {
+      toast.success('Order rejected')
+      setRejectModalOpen(false)
+      setRejectReason('')
+      qc.invalidateQueries({ queryKey: ['order', id] })
+      qc.invalidateQueries({ queryKey: ['orders'] })
+    },
+    onError: (e: any) => toast.error(e.response?.data?.detail || 'Reject failed'),
+  })
+
+  const resubmitMut = useMutation({
+    mutationFn: () => resubmitOrder(id!),
+    onSuccess: () => {
+      toast.success('Order moved back to draft')
+      qc.invalidateQueries({ queryKey: ['order', id] })
+      qc.invalidateQueries({ queryKey: ['orders'] })
+    },
+    onError: (e: any) => toast.error(e.response?.data?.detail || 'Resubmit failed'),
+  })
+
   if (isLoading) return <div className="p-8 text-center text-content-muted">Loading…</div>
   if (!order) return <div className="p-8 text-center text-red-500">Order not found</div>
 
@@ -155,6 +181,8 @@ export default function OrderDetailPage() {
   const canDelete = order.status === 'draft' || order.status === 'rejected'
   const isDraft = order.status === 'draft'
   const isPrivileged = user?.role === 'admin' || user?.role === 'project_manager'
+  const canReject = isPrivileged && (order.status === 'submitted' || order.status === 'processing')
+  const canResubmit = order.status === 'rejected' && (isPrivileged || order.created_by === user?.id)
   const rp = order.render_progress
   const hasRetryable = rp && (rp.pending > 0 || rp.failed > 0 || (rp as any).cancelled > 0)
   const canDispatch = isPrivileged && (order.status === 'processing' || order.status === 'submitted' || order.status === 'completed')
@@ -272,6 +300,25 @@ export default function OrderDetailPage() {
                   : 'Dispatch Renders'}
           </button>
         )}
+        {canReject && (
+          <button
+            onClick={() => setRejectModalOpen(true)}
+            className="px-3 py-2 rounded-lg text-sm font-medium border border-red-300 text-red-600 bg-red-50 hover:bg-red-100 transition-colors disabled:opacity-50 flex items-center gap-1.5"
+          >
+            <XCircle size={16} />
+            Reject Order
+          </button>
+        )}
+        {canResubmit && (
+          <button
+            onClick={() => resubmitMut.mutate()}
+            className="px-3 py-2 rounded-lg text-sm font-medium border border-border-default text-content-secondary bg-surface hover:bg-surface-hover transition-colors disabled:opacity-50 flex items-center gap-1.5"
+            disabled={resubmitMut.isPending}
+          >
+            <RotateCw size={16} />
+            {resubmitMut.isPending ? 'Moving to draft…' : 'Resubmit (back to draft)'}
+          </button>
+        )}
         {canSubmit && (
           <button
             onClick={() => submitMut.mutate()}
@@ -381,6 +428,22 @@ export default function OrderDetailPage() {
         </div>
       )}
 
+      {order.status === 'rejected' && order.rejection_reason && (
+        <div className="card p-4 mb-6 bg-amber-50 border-amber-300 border flex items-start gap-3">
+          <XCircle size={18} className="text-red-500 shrink-0 mt-0.5" />
+          <div>
+            <p className="text-sm font-semibold text-red-700">Order Rejected</p>
+            <p className="text-sm text-amber-800 mt-0.5">{order.rejection_reason}</p>
+          </div>
+        </div>
+      )}
+      {order.status === 'rejected' && !order.rejection_reason && (
+        <div className="card p-4 mb-6 bg-red-50 border-red-200 border flex items-center gap-3">
+          <XCircle size={18} className="text-red-500 shrink-0" />
+          <p className="text-sm font-semibold text-red-700">This order was rejected.</p>
+        </div>
+      )}
+
       {order.notes && (
         <div className="card p-4 mb-6 bg-status-info-bg border-border-default">
           <p className="text-sm text-status-info-text">{order.notes}</p>
@@ -688,6 +751,64 @@ export default function OrderDetailPage() {
         )}
       </div>
 
+      {/* Reject Order Modal */}
+      {rejectModalOpen && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/40">
+          <div className="bg-surface rounded-xl shadow-2xl border border-border-default w-full max-w-md mx-4 p-6">
+            <div className="flex items-center gap-3 mb-4">
+              <XCircle size={20} className="text-red-500 shrink-0" />
+              <h2 className="text-lg font-semibold text-content">Reject Order</h2>
+              <button
+                onClick={() => { setRejectModalOpen(false); setRejectReason('') }}
+                className="ml-auto p-1 text-content-muted hover:text-content transition-colors rounded"
+              >
+                <X size={16} />
+              </button>
+            </div>
+            <p className="text-sm text-content-secondary mb-4">
+              Rejecting <span className="font-semibold font-mono">{order.order_number}</span> will
+              cancel all pending renders and move the order to &ldquo;rejected&rdquo; status.
+            </p>
+            <div className="mb-4">
+              <label className="block text-xs font-medium text-content-secondary mb-1.5">
+                Rejection reason (optional)
+              </label>
+              <textarea
+                value={rejectReason}
+                onChange={(e) => setRejectReason(e.target.value)}
+                placeholder="Describe why this order is being rejected…"
+                rows={3}
+                className="w-full px-3 py-2 text-sm border border-border-default rounded-lg bg-surface-alt focus:outline-none focus:ring-2 focus:ring-accent resize-none"
+              />
+            </div>
+            <label className="flex items-center gap-2 text-sm text-content-secondary mb-5 cursor-pointer select-none">
+              <input
+                type="checkbox"
+                checked={rejectNotifyClient}
+                onChange={(e) => setRejectNotifyClient(e.target.checked)}
+                className="w-4 h-4 rounded accent-accent"
+              />
+              Notify the order creator
+            </label>
+            <div className="flex items-center gap-3 justify-end">
+              <button
+                onClick={() => { setRejectModalOpen(false); setRejectReason('') }}
+                className="btn-secondary"
+              >
+                Cancel
+              </button>
+              <button
+                onClick={() => rejectMut.mutate()}
+                disabled={rejectMut.isPending}
+                className="px-4 py-2 rounded-lg text-sm font-semibold bg-red-600 hover:bg-red-700 text-white transition-colors disabled:opacity-50 flex items-center gap-2"
+              >
+                <XCircle size={15} />
+                {rejectMut.isPending ? 'Rejecting…' : 'Confirm Rejection'}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   )
 }

frontend/src/pages/Orders.tsx

@@ -711,7 +711,12 @@ function KanbanCard({
       {rp && rp.total > 0 && (
         <RenderProgressBar progress={rp} />
       )}
-      {order.notes && !rp && (
+      {order.status === 'rejected' && order.rejection_reason && (
+        <p className="mt-2 text-xs text-red-500 italic truncate" title={order.rejection_reason}>
+          {order.rejection_reason}
+        </p>
+      )}
+      {order.notes && !rp && order.status !== 'rejected' && (
         <p className="mt-2 text-xs text-content-muted truncate">{order.notes}</p>
       )}
       <div className="mt-2 flex items-center justify-end opacity-0 group-hover:opacity-100 transition-opacity">