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/src/components/OccupancyGrid.tsx

@@ -0,0 +1,147 @@
+import { useEffect, useMemo, useRef } from 'react';
+import { StyleProp, ViewStyle } from 'react-native';
+import Animated, { interpolateColor, useAnimatedProps, useSharedValue, withTiming, type SharedValue } from 'react-native-reanimated';
+import Svg, { Circle, G, Rect } from 'react-native-svg';
+import { colors } from '../theme/colors';
+
+type Point = {
+  x: number;
+  y: number;
+};
+
+type OccupancyGridProps = {
+  values: number[];
+  personPositions?: Point[];
+  size?: number;
+  style?: StyleProp<ViewStyle>;
+};
+
+const GRID_DIMENSION = 20;
+const CELLS = GRID_DIMENSION * GRID_DIMENSION;
+
+const toColor = (value: number): string => {
+  const clamped = Math.max(0, Math.min(1, value));
+  let r: number;
+  let g: number;
+  let b: number;
+
+  if (clamped < 0.5) {
+    const t = clamped * 2;
+    r = Math.round(255 * 0);
+    g = Math.round(255 * t);
+    b = Math.round(255 * (1 - t));
+  } else {
+    const t = (clamped - 0.5) * 2;
+    r = Math.round(255 * t);
+    g = Math.round(255 * (1 - t));
+    b = 0;
+  }
+
+  return `rgb(${r}, ${g}, ${b})`;
+};
+
+const AnimatedRect = Animated.createAnimatedComponent(Rect);
+
+const normalizeValues = (values: number[]) => {
+  const normalized = new Array(CELLS).fill(0);
+  for (let i = 0; i < CELLS; i += 1) {
+    const value = values?.[i] ?? 0;
+    normalized[i] = Number.isFinite(value) ? Math.max(0, Math.min(1, value)) : 0;
+  }
+  return normalized;
+};
+
+type CellProps = {
+  index: number;
+  size: number;
+  progress: SharedValue<number>;
+  previousColors: string[];
+  nextColors: string[];
+};
+
+const Cell = ({ index, size, progress, previousColors, nextColors }: CellProps) => {
+  const col = index % GRID_DIMENSION;
+  const row = Math.floor(index / GRID_DIMENSION);
+  const cellSize = size / GRID_DIMENSION;
+  const x = col * cellSize;
+  const y = row * cellSize;
+
+  const animatedProps = useAnimatedProps(() => ({
+    fill: interpolateColor(
+      progress.value,
+      [0, 1],
+      [previousColors[index] ?? colors.surfaceAlt, nextColors[index] ?? colors.surfaceAlt],
+    ),
+  }));
+
+  return (
+    <AnimatedRect
+      x={x}
+      y={y}
+      width={cellSize}
+      height={cellSize}
+      rx={1}
+      animatedProps={animatedProps}
+    />
+  );
+};
+
+export const OccupancyGrid = ({
+  values,
+  personPositions = [],
+  size = 320,
+  style,
+}: OccupancyGridProps) => {
+  const normalizedValues = useMemo(() => normalizeValues(values), [values]);
+  const previousColors = useRef<string[]>(normalizedValues.map(toColor));
+  const nextColors = useRef<string[]>(normalizedValues.map(toColor));
+  const progress = useSharedValue(1);
+
+  useEffect(() => {
+    const next = normalizeValues(values);
+    previousColors.current = normalizedValues.map(toColor);
+    nextColors.current = next.map(toColor);
+    progress.value = 0;
+    progress.value = withTiming(1, { duration: 500 });
+  }, [values, normalizedValues, progress]);
+
+  const markers = useMemo(() => {
+    const cellSize = size / GRID_DIMENSION;
+    return personPositions.map(({ x, y }, idx) => {
+      const clampedX = Math.max(0, Math.min(GRID_DIMENSION - 1, Math.round(x)));
+      const clampedY = Math.max(0, Math.min(GRID_DIMENSION - 1, Math.round(y)));
+      const cx = (clampedX + 0.5) * cellSize;
+      const cy = (clampedY + 0.5) * cellSize;
+      const markerRadius = Math.max(3, cellSize * 0.25);
+      return (
+        <Circle
+          key={`person-${idx}`}
+          cx={cx}
+          cy={cy}
+          r={markerRadius}
+          fill={colors.accent}
+          stroke={colors.textPrimary}
+          strokeWidth={1}
+        />
+      );
+    });
+  }, [personPositions, size]);
+
+  return (
+    <Svg width={size} height={size} style={style} viewBox={`0 0 ${size} ${size}`}>
+      <G>
+        {Array.from({ length: CELLS }).map((_, index) => (
+          <Cell
+            key={index}
+            index={index}
+            size={size}
+            progress={progress}
+            previousColors={previousColors.current}
+            nextColors={nextColors.current}
+          />
+        ))}
+      </G>
+      {markers}
+    </Svg>
+  );
+};