feat: Implement RSSI service for iOS and Web platforms

- Added IosRssiService to handle synthetic RSSI data for iOS.
- Created WebRssiService to simulate RSSI scanning on the web.
- Defined shared types for WifiNetwork and RssiService in rssi.service.ts.
- Introduced simulation service to generate synthetic sensing data.
- Implemented WebSocket service for real-time data handling with reconnection logic.
- Established Zustand stores for managing application state related to MAT and pose data.
- Developed theme context and utility functions for consistent styling and formatting.
- Added type definitions for various application entities including API responses and sensing data.
- Created utility functions for color mapping and URL validation.
- Configured TypeScript settings for the mobile application.

ui/mobile/App.tsx

@@ -0,0 +1,74 @@
+import { useEffect } from 'react';
+import { NavigationContainer, DarkTheme } from '@react-navigation/native';
+import { GestureHandlerRootView } from 'react-native-gesture-handler';
+import { StatusBar } from 'expo-status-bar';
+import { SafeAreaProvider } from 'react-native-safe-area-context';
+import { apiService } from '@/services/api.service';
+import { rssiService } from '@/services/rssi.service';
+import { wsService } from '@/services/ws.service';
+import { ThemeProvider } from './src/theme/ThemeContext';
+import { usePoseStore } from './src/stores/poseStore';
+import { useSettingsStore } from './src/stores/settingsStore';
+import { RootNavigator } from './src/navigation/RootNavigator';
+
+export default function App() {
+  const serverUrl = useSettingsStore((state) => state.serverUrl);
+  const rssiScanEnabled = useSettingsStore((state) => state.rssiScanEnabled);
+
+  useEffect(() => {
+    apiService.setBaseUrl(serverUrl);
+    const unsubscribe = wsService.subscribe(usePoseStore.getState().handleFrame);
+    wsService.connect(serverUrl);
+
+    return () => {
+      unsubscribe();
+      wsService.disconnect();
+    };
+  }, [serverUrl]);
+
+  useEffect(() => {
+    if (!rssiScanEnabled) {
+      rssiService.stopScanning();
+      return;
+    }
+
+    const unsubscribe = rssiService.subscribe(() => {
+      // Consumers can subscribe elsewhere for RSSI events.
+    });
+    rssiService.startScanning(2000);
+
+    return () => {
+      unsubscribe();
+      rssiService.stopScanning();
+    };
+  }, [rssiScanEnabled]);
+
+  useEffect(() => {
+    (globalThis as { __appStartTime?: number }).__appStartTime = Date.now();
+  }, []);
+
+  const navigationTheme = {
+    ...DarkTheme,
+    colors: {
+      ...DarkTheme.colors,
+      background: '#0A0E1A',
+      card: '#0D1117',
+      text: '#E2E8F0',
+      border: '#1E293B',
+      primary: '#32B8C6',
+    },
+  };
+
+  return (
+    <GestureHandlerRootView style={{ flex: 1 }}>
+      <SafeAreaProvider>
+        <ThemeProvider>
+          <NavigationContainer theme={navigationTheme}>
+            <RootNavigator />
+          </NavigationContainer>
+        </ThemeProvider>
+      </SafeAreaProvider>
+      <StatusBar style="light" />
+    </GestureHandlerRootView>
+  );
+}