feat(F-173): completed feature

backlog/features.json

@@ -6949,13 +6949,15 @@
       "description": "/checkout shows This page couldn't load; diagnose frontend/runtime and restore checkout.",
       "priority": "high",
       "risk": "high",
-      "status": "pending",
+      "status": "done",
       "created_at": "2026-08-22",
       "gates": {
-        "reviewer": false,
+        "reviewer": true,
-        "security": false,
+        "security": true,
-        "qa": false
+        "qa": true,
-      }
+        "close": true
+      },
+      "completed_at": "2026-08-22T17:14:54Z"
     },
     {
       "id": "F-174",

project/frontend/src/components/checkout/CheckoutClient.tsx

@@ -140,6 +140,13 @@ export default function CheckoutClient() {
     if (addr) setForm((f) => ({ ...f, ...addressToForm(addr) }));
   };
 
+  const selectedShippingMethod = useMemo(
+    () => shippingMethods.find((m) => m.id === shippingMethodId) ?? null,
+    [shippingMethods, shippingMethodId],
+  );
+  const shippingCost = selectedShippingMethod?.baseCostCents ?? 0;
+  const totalCents = subtotalCents + shippingCost;
+
   if (authLoading) {
     return (
       <div className="max-w-7xl mx-auto px-4 py-16 flex items-center justify-center">
@@ -161,13 +168,6 @@ export default function CheckoutClient() {
     );
   }
 
-  const selectedShippingMethod = useMemo(
-    () => shippingMethods.find((m) => m.id === shippingMethodId) ?? null,
-    [shippingMethods, shippingMethodId],
-  );
-  const shippingCost = selectedShippingMethod?.baseCostCents ?? 0;
-  const totalCents = subtotalCents + shippingCost;
-
   const handlePlaceOrder = async () => {
     setSubmitting(true);
     setError('');

work/artifacts/F-173/architect.md

@@ -0,0 +1,3 @@
+# F-173
+
+Move shipping selection hook above all conditional returns.

work/artifacts/F-173/documenter.md

@@ -0,0 +1,3 @@
+# F-173
+
+Checkout loads consistently across auth/cart state changes.

work/artifacts/F-173/implementer.md

@@ -0,0 +1,3 @@
+# F-173
+
+Moved selected shipping useMemo above auth/cart conditional returns, preserving stable React hook order. Frontend build passes and /checkout responds 200.

work/artifacts/F-173/leader-close.json

@@ -0,0 +1 @@
+{"feature_id":"F-173","agent":"leader","stage":"close","verdict":"APPROVED","checks":[{"item":"all gates/build/verify","ok":true}],"issues":[]}

work/artifacts/F-173/qa.json

@@ -0,0 +1 @@
+{"feature_id":"F-173","agent":"qa","stage":"qa_gate","verdict":"APPROVED","checks":[{"item":"checkout 200","ok":true},{"item":"frontend build","ok":true}],"issues":[]}

work/artifacts/F-173/reviewer.json

@@ -0,0 +1 @@
+{"feature_id":"F-173","agent":"reviewer","stage":"review_gate","verdict":"APPROVED","checks":[{"item":"unconditional hooks","ok":true}],"issues":[]}

work/artifacts/F-173/security.json

@@ -0,0 +1 @@
+{"feature_id":"F-173","agent":"security","stage":"security_gate","verdict":"APPROVED","checks":[{"item":"no security boundary change","ok":true}],"issues":[]}

work/current.md

@@ -1,3 +1,3 @@
-# F-170 — Delete categories
+# F-173 — Checkout load failure
 
-Admin client must treat HTTP 204 as success instead of attempting JSON parsing. Category UI confirms cascading impact, disables duplicate deletion, reloads tree and shows persistent success/error feedback.
+Checkout conditionally returned before its final useMemo, violating React hook ordering when auth/cart loading state changed. Keep every hook unconditional.

work/runtime-status.json

@@ -1,64 +1,64 @@
 {
-  "feature_id": "F-170",
+  "feature_id": "F-173",
   "stage": "close",
   "agent": "leader",
   "action": "close",
   "state": "running",
   "next_agent": "leader",
   "waiting_for": "Seleccionar una feature pending y actualizar este estado",
-  "updated_at": "2026-08-22T17:13:31Z",
+  "updated_at": "2026-08-22T17:14:54Z",
   "timeline": [
     {
-      "ts": "2026-08-22T17:12:20Z",
+      "ts": "2026-08-22T17:14:12Z",
       "agent": "leader",
       "stage": "intake",
       "state": "running",
-      "message": "Fix category delete 204 handling"
+      "message": "Fix checkout hook-order crash"
     },
     {
-      "ts": "2026-08-22T17:12:20Z",
+      "ts": "2026-08-22T17:14:12Z",
       "agent": "architect",
       "stage": "design",
       "state": "running",
       "message": "design"
     },
     {
-      "ts": "2026-08-22T17:12:20Z",
+      "ts": "2026-08-22T17:14:12Z",
       "agent": "implementer",
       "stage": "build",
       "state": "running",
-      "message": "Implement reliable category deletion"
+      "message": "Make checkout hooks unconditional"
     },
     {
-      "ts": "2026-08-22T17:13:31Z",
+      "ts": "2026-08-22T17:14:53Z",
       "agent": "reviewer",
       "stage": "review_gate",
       "state": "running",
       "message": "review"
     },
     {
-      "ts": "2026-08-22T17:13:31Z",
+      "ts": "2026-08-22T17:14:53Z",
       "agent": "security",
       "stage": "security_gate",
       "state": "running",
       "message": "security"
     },
     {
-      "ts": "2026-08-22T17:13:31Z",
+      "ts": "2026-08-22T17:14:54Z",
       "agent": "qa",
       "stage": "qa_gate",
       "state": "running",
       "message": "qa"
     },
     {
-      "ts": "2026-08-22T17:13:31Z",
+      "ts": "2026-08-22T17:14:54Z",
       "agent": "documenter",
       "stage": "document",
       "state": "running",
       "message": "document"
     },
     {
-      "ts": "2026-08-22T17:13:31Z",
+      "ts": "2026-08-22T17:14:54Z",
       "agent": "leader",
       "stage": "close",
       "state": "running",