PackagesStep: look up selected package in both primary + same-provider-more lists

Clicking a package in the "Other packages from [Provider]" section set
the selectedPackageId correctly but the detail panel stayed on the empty
state — `selectedPackage` was derived only from the primary `packages`
array, so secondary-list ids never resolved. Now falls back to the
secondary list when the primary miss.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/pages/PackagesStep/PackagesStep.tsx

@@ -214,7 +214,14 @@ export const PackagesStep: React.FC<PackagesStepProps> = ({
   sx,
 }) => {
   const copy = TIER_COPY[providerTier];
-  const selectedPackage = packages.find((p) => p.id === selectedPackageId);
+  // Look up the selected package across BOTH the primary list and the
+  // same-provider-more secondary list — tapping "Premium Funeral Service"
+  // in the "Other packages from X" section should surface its detail too.
+  const selectedPackage =
+    packages.find((p) => p.id === selectedPackageId) ??
+    (secondaryList?.kind === 'same-provider-more'
+      ? secondaryList.packages.find((p) => p.id === selectedPackageId)
+      : undefined);
 
   // Mobile drill-in: on mobile, the list is the default view — only when the
   // user explicitly taps a package do we swap in the detail panel. This