orders: fix the 42703 that broke EVERY order detail page

getOrderDetail joined order_merchant_cadence on merchant_entity_id. Migration
021 rekeyed that view to merchant_key (merchant_entity_id is NULL on ~9% of the
feed, and duplicate merchant entities split one shop's history); 027 and 029
moved order_feed and order_spend across, and this query was missed. Every
/orders/<key> request has since failed with

  column rec.merchant_entity_id does not exist

The reason nobody saw a 500 is the second half of this commit: the page
collapsed every failure into 'That order could not be found.' A server fault
wearing the costume of a data condition reads as an empty spine and gets
investigated in the wrong repo. The hook now carries the status and only a
genuine 404 says the order is missing.

src/app/orders/[entityKey]/page.tsx

@@ -63,10 +63,22 @@ export default function OrderDetailPage({ params }: { params: Promise<{ entityKe
 
   if (isLoading) return <div className="p-6 text-zinc-500 text-sm">Loading order…</div>;
   if (error || !o) {
+    // A missing order and a broken query are different problems and must not
+    // share a sentence. Only a 404 means "no such order"; anything else is this
+    // page failing, and saying so is what sends the next person to the server
+    // log instead of to the spine.
+    const status = (error as (Error & { status?: number }) | null)?.status;
     return (
       <div className="max-w-[1180px] mx-auto">
         <Link href="/orders" className="font-mono text-[11.5px] text-indigo-400">← All orders</Link>
+        {status === 404 ? (
           <p className="mt-6 text-zinc-400 text-sm">That order could not be found.</p>
+        ) : (
+          <p className="mt-6 text-zinc-400 text-sm">
+            This order could not be loaded{status ? ` (server error ${status})` : ""}. The order exists —
+            something in this page failed. Check the finance-app log.
+          </p>
+        )}
       </div>
     );
   }

src/lib/hooks.ts

@@ -1243,7 +1243,16 @@ export function useOrderDetail(entityKey: string | null) {
     staleTime: 60_000,
     queryFn: async () => {
       const res = await fetch(`/api/orders/${encodeURIComponent(entityKey!)}`);
-      if (!res.ok) throw new Error("Failed to load order");
+      if (!res.ok) {
+        // Carry the status. Collapsing every failure into one Error is how a
+        // 500 on this route rendered as "that order could not be found" on
+        // every single order for weeks — a server fault wearing the costume of
+        // a data condition, which reads as "the spine is empty" and gets
+        // investigated nowhere near the actual bug.
+        const err = new Error(res.status === 404 ? "Order not found" : "Failed to load order");
+        (err as Error & { status?: number }).status = res.status;
+        throw err;
+      }
       return res.json();
     },
   });

src/lib/order-feed.ts

@@ -73,6 +73,12 @@ export interface OrderRow {
   /** Merchant orders on a regular cadence: the subscription signal, derived
    *  not extracted. NULL unless the gaps are tight relative to their mean. */
   cadence_days: number | null;
+  /** Worst sender-authentication verdict across the order's source documents.
+   *  93% are 'pass' — the badge exists for the 7% that are not. Do NOT badge
+   *  source_trust instead: it is 'untrusted_external' on 100% of rows, because
+   *  every order here came from email. */
+  auth_verdict: string | null;
+  injection_flagged: boolean | null;
   txn_count: number;
   first_txn_id: number | null;
 }
@@ -220,6 +226,7 @@ export async function getOrderFeed(filters: OrderFilters) {
             f.ordered_at, f.eta_date, f.delivered_at,
             f.currency, f.order_total, f.line_item_count,
             f.content_class, f.display_name, f.cadence_days,
+            f.auth_verdict, f.injection_flagged,
             m.canonical_name   AS merchant_name,
             link.txn_count, link.first_txn_id,
             (SELECT sp.refunded_amount FROM order_spend sp
@@ -399,7 +406,16 @@ export async function getOrderDetail(entityKey: string): Promise<OrderDetail | n
        LEFT JOIN entities me2 ON me2.id = o.merchant_entity_id
        LEFT JOIN order_platforms p ON p.slug = o.platform
        LEFT JOIN order_spend sp ON sp.entity_id = o.entity_id
-       LEFT JOIN order_merchant_cadence rec ON rec.merchant_entity_id = o.merchant_entity_id
+       -- Cadence is keyed on the NORMALISED MERCHANT NAME, not merchant_entity_id.
+       -- Migration 021 rekeyed the view (that column is NULL on ~9% of the feed
+       -- and duplicate merchant entities split the same shop's history); 027 and
+       -- 029 moved order_feed/order_spend onto merchant_key, and this query was
+       -- missed. The result was a 42703 on EVERY order detail page — the join
+       -- referenced a column the view no longer had. Keep this expression
+       -- identical to the one in migration 027.
+       LEFT JOIN order_merchant_cadence rec
+              ON rec.merchant_key = regexp_replace(
+                   lower(COALESCE(me2.canonical_name, o.platform)), '[^a-z0-9]', '', 'g')
        LEFT JOIN LATERAL (
          SELECT di.content_class, di.counterparty
            FROM extracted_facts ef