Changes

Co-authored-by: renee-png <262607627+renee-png@users.noreply.github.com>

src/routes/collections.$collectionId.tsx

@@ -292,14 +292,21 @@ function CollectionDetailRoute() {
   return (
     <ProtectedLayout>
       <PageContainer>
-        <Button
-          variant="ghost"
-          size="sm"
-          onClick={() => navigate({ to: "/collections" })}
-          className="-ml-2 mb-3"
-        >
-          <ArrowLeft className="h-4 w-4 mr-1" /> All collections
-        </Button>
+        <div className="flex items-center justify-between gap-2 mb-3">
+          <Button
+            variant="ghost"
+            size="sm"
+            onClick={() => navigate({ to: "/collections" })}
+            className="-ml-2"
+          >
+            <ArrowLeft className="h-4 w-4 mr-1" /> All collections
+          </Button>
+          {collection.case?.client?.id && (
+            <Button size="sm" onClick={() => setInvoiceOpen(true)}>
+              <FilePlus className="h-4 w-4 mr-1.5" /> Generate invoice
+            </Button>
+          )}
+        </div>
 
         {/* Tabs: Workflow (collections-specific) + same case tabs */}
         <Tabs defaultValue="workflow">