feat: Initialize Turtle Control Center with React and WebSocket server

- Added index.html for the main entry point of the client application.
- Created package.json for client dependencies and scripts.
- Implemented App component with view controls and layout.
- Added CSS styles for the application and components.
- Developed ControlPanel component for turtle management and commands.
- Created Map3D component for 3D visualization of turtles.
- Established Zustand store for state management of turtles and WebSocket connection.
- Set up server with Express and WebSocket for handling turtle updates and commands.
- Added REST API endpoints for turtle status updates and command handling.
- Implemented start.sh script for setting up and running the application.

client/src/App.css

@@ -0,0 +1,93 @@
+.app {
+  width: 100vw;
+  height: 100vh;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+
+.view-controls {
+  display: flex;
+  gap: 0.5rem;
+  padding: 0.75rem;
+  background: #1e293b;
+  border-bottom: 2px solid #334155;
+}
+
+.view-controls button {
+  padding: 0.5rem 1rem;
+  border: none;
+  background: #334155;
+  color: #e2e8f0;
+  border-radius: 0.375rem;
+  font-size: 0.875rem;
+  font-weight: 600;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.view-controls button:hover {
+  background: #475569;
+  transform: translateY(-1px);
+}
+
+.view-controls button.active {
+  background: #3b82f6;
+  color: white;
+  box-shadow: 0 0 10px rgba(59, 130, 246, 0.5);
+}
+
+.app-content {
+  flex: 1;
+  display: flex;
+  overflow: hidden;
+}
+
+.app-content.split {
+  display: flex;
+}
+
+.app-content.split .map-container {
+  flex: 1;
+}
+
+.app-content.split .panel-container {
+  width: 600px;
+}
+
+.app-content.map .panel-container {
+  display: none;
+}
+
+.app-content.panel .map-container {
+  display: none;
+}
+
+.map-container {
+  position: relative;
+  background: #0a0e1a;
+}
+
+.panel-container {
+  background: #0f172a;
+  overflow: hidden;
+}
+
+/* Scrollbar styling */
+::-webkit-scrollbar {
+  width: 8px;
+  height: 8px;
+}
+
+::-webkit-scrollbar-track {
+  background: #1e293b;
+}
+
+::-webkit-scrollbar-thumb {
+  background: #475569;
+  border-radius: 4px;
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background: #64748b;
+}