feat(client): add study session page with card flip and rating UI

Implements the complete study flow frontend:
- Study session page with card display and flip interaction
- Rating buttons (Again, Hard, Good, Easy) with keyboard shortcuts
- Progress display showing remaining cards count
- Session complete screen with review summary
- Study Now button on deck detail page

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/client/App.tsx b/src/client/App.tsx
index 4c5b08a..f774003 100644
--- a/src/client/App.tsx
+++ b/src/client/App.tsx
@@ -1,6 +1,12 @@
 import { Route, Switch } from "wouter";
 import { ProtectedRoute } from "./components";
-import { DeckDetailPage, HomePage, LoginPage, NotFoundPage } from "./pages";
+import {
+	DeckDetailPage,
+	HomePage,
+	LoginPage,
+	NotFoundPage,
+	StudyPage,
+} from "./pages";
 
 export function App() {
 	return (
@@ -15,6 +21,11 @@ export function App() {
 					<DeckDetailPage />
 				</ProtectedRoute>
 			</Route>
+			<Route path="/decks/:deckId/study">
+				<ProtectedRoute>
+					<StudyPage />
+				</ProtectedRoute>
+			</Route>
 			<Route path="/login" component={LoginPage} />
 			<Route component={NotFoundPage} />
 		</Switch>