feat(drill): hover affordance CSS + App wrapped in DrillStackProvider

src/App.tsx

@@ -1,6 +1,7 @@
 import { Route, Routes } from "react-router-dom";
 import { Toaster } from "sonner";
 import { Layout } from "@/components/Layout";
+import { DrillStackProvider } from "@/components/drill/DrillStackProvider";
 import { Dashboard } from "@/pages/Dashboard";
 import { Claims } from "@/pages/Claims";
 import { Remittances } from "@/pages/Remittances";
@@ -24,7 +25,7 @@ function NotFound() {
 
 export default function App() {
   return (
-    <>
+    <DrillStackProvider>
       <Routes>
         <Route element={<Layout />}>
           <Route index element={<Dashboard />} />
@@ -52,6 +53,6 @@ export default function App() {
           },
         }}
       />
-    </>
+    </DrillStackProvider>
   );
 }

src/index.css

@@ -413,3 +413,18 @@
     animation-duration: 0s !important;
   }
 }
+
+/* Universal drill-down affordance — applied by DrillableCell. */
+.drillable {
+  cursor: pointer;
+  transition: background-color 120ms ease;
+}
+.drillable:hover {
+  background-color: hsl(var(--accent) / 0.08);
+}
+.drillable:hover::after {
+  content: "›";
+  margin-left: 6px;
+  color: hsl(var(--accent));
+  font-weight: 600;
+}