feat: add Home page with user dashboard and habit tracking features

- Implemented Home component with user authentication and loading states.
- Created Welcome component for unauthenticated users with a sign-in option.
- Developed Dashboard component to display user's habits and progress.
- Added functionality for habit management, including adding, updating, and deleting habits.
- Integrated HabitChart and HabitHistory components for visual representation of habits.
- Introduced sharing functionality for progress via Discord integration.

feat: establish Discord sharing configuration and routes

- Added DiscordSharingConfig type and readDiscordSharingConfig function for environment variable management.
- Created sharing contracts for input validation and data structure.
- Implemented sharing routes for previewing and sending progress images to Discord.
- Added tests for sharing routes to ensure authentication and proper error handling.

src/App.tsx

@@ -1,11 +1,21 @@
 import { Navigate, Route, Routes } from "react-router";
 import { DesignSystem } from "./pages/DesignSystem";
+import { Home } from "./pages/Home";
+import { AuthProvider } from "./components/AuthProvider";
 
 export function App() {
   return (
     <Routes>
       <Route path="/design-system" element={<DesignSystem />} />
-      <Route path="*" element={<Navigate to="/design-system" replace />} />
+      <Route
+        path="/"
+        element={
+          <AuthProvider>
+            <Home />
+          </AuthProvider>
+        }
+      />
+      <Route path="*" element={<Navigate to="/" replace />} />
     </Routes>
   );
 }