feat: Initialize frontend and backend structure with essential configurations

- Added TypeScript build info for frontend.
- Created Vite configuration for React application.
- Implemented pre-commit hook to run checks before commits.
- Set up PostgreSQL Dockerfile with PostGIS support and initialization scripts.
- Added database creation script for PostgreSQL with necessary extensions.
- Established Python project configuration with dependencies and development tools.
- Developed pre-commit script to enforce code quality checks for backend and frontend.
- Created PowerShell script to set up Git hooks path.

frontend/src/App.tsx

@@ -0,0 +1,88 @@
+import './styles/global.css';
+
+import { LoginForm } from './components/auth/LoginForm';
+import { NetworkMap } from './components/map/NetworkMap';
+import { useNetworkSnapshot } from './hooks/useNetworkSnapshot';
+import { useAuth } from './state/AuthContext';
+
+function App(): JSX.Element {
+  const { token, user, status: authStatus, logout } = useAuth();
+  const isAuthenticated = authStatus === 'authenticated' && token !== null;
+  const { data, status, error } = useNetworkSnapshot(isAuthenticated ? token : null);
+
+  return (
+    <div className="app-shell">
+      <header className="app-header">
+        <div>
+          <h1>Rail Game</h1>
+          <p>Build and manage a railway network using real-world map data.</p>
+        </div>
+        {isAuthenticated && (
+          <div className="auth-meta">
+            <span>Signed in as {user?.fullName ?? user?.username}</span>
+            <button type="button" onClick={() => logout()} className="ghost-button">
+              Sign out
+            </button>
+          </div>
+        )}
+      </header>
+      <main className="app-main">
+        {!isAuthenticated ? (
+          <section className="card">
+            <LoginForm />
+          </section>
+        ) : (
+          <section className="card">
+            <h2>Network Snapshot</h2>
+            {status === 'loading' && <p>Loading network data…</p>}
+            {status === 'error' && <p className="error-text">{error}</p>}
+            {status === 'success' && data && (
+              <div className="snapshot-layout">
+                <div className="map-wrapper">
+                  <NetworkMap snapshot={data} />
+                </div>
+                <div className="grid">
+                  <div>
+                    <h3>Stations</h3>
+                    <ul>
+                      {data.stations.map((station) => (
+                        <li key={station.id}>
+                          {station.name} ({station.latitude.toFixed(3)},{' '}
+                          {station.longitude.toFixed(3)})
+                        </li>
+                      ))}
+                    </ul>
+                  </div>
+                  <div>
+                    <h3>Trains</h3>
+                    <ul>
+                      {data.trains.map((train) => (
+                        <li key={train.id}>
+                          {train.designation} · {train.capacity} capacity ·{' '}
+                          {train.maxSpeedKph} km/h
+                        </li>
+                      ))}
+                    </ul>
+                  </div>
+                  <div>
+                    <h3>Tracks</h3>
+                    <ul>
+                      {data.tracks.map((track) => (
+                        <li key={track.id}>
+                          {track.startStationId} → {track.endStationId} ·{' '}
+                          {(track.lengthMeters / 1000).toFixed(1)} km
+                        </li>
+                      ))}
+                    </ul>
+                  </div>
+                </div>
+              </div>
+            )}
+          </section>
+        )}
+      </main>
+    </div>
+  );
+}
+
+export default App;