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/utils/colorMap.ts

@@ -0,0 +1,21 @@
+export function valueToColor(v: number): [number, number, number] {
+  const clamped = Math.max(0, Math.min(1, v));
+
+  let r: number;
+  let g: number;
+  let b: number;
+
+  if (clamped < 0.5) {
+    const t = clamped * 2;
+    r = 0;
+    g = t;
+    b = 1 - t;
+  } else {
+    const t = (clamped - 0.5) * 2;
+    r = t;
+    g = 1 - t;
+    b = 0;
+  }
+
+  return [r, g, b];
+}

ui/mobile/src/utils/formatters.ts

@@ -0,0 +1,34 @@
+export function formatRssi(v: number | null | undefined): string {
+  if (typeof v !== 'number' || !Number.isFinite(v)) {
+    return '-- dBm';
+  }
+  return `${Math.round(v)} dBm`;
+}
+
+export function formatBpm(v: number | null | undefined): string {
+  if (typeof v !== 'number' || !Number.isFinite(v)) {
+    return '--';
+  }
+  return `${Math.round(v)} BPM`;
+}
+
+export function formatConfidence(v: number | null | undefined): string {
+  if (typeof v !== 'number' || !Number.isFinite(v)) {
+    return '--';
+  }
+  const normalized = v > 1 ? v / 100 : v;
+  return `${Math.round(Math.max(0, Math.min(1, normalized)) * 100)}%`;
+}
+
+export function formatUptime(ms: number | null | undefined): string {
+  if (typeof ms !== 'number' || !Number.isFinite(ms) || ms < 0) {
+    return '--:--:--';
+  }
+
+  const totalSeconds = Math.floor(ms / 1000);
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = totalSeconds % 60;
+
+  return `${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}`;
+}

ui/mobile/src/utils/ringBuffer.ts

@@ -0,0 +1,48 @@
+export class RingBuffer<T> {
+  private readonly capacity: number;
+  private readonly compare?: (a: T, b: T) => number;
+  private readonly values: T[] = [];
+
+  constructor(capacity: number, compare?: (a: T, b: T) => number) {
+    if (!Number.isFinite(capacity) || capacity <= 0) {
+      throw new Error('RingBuffer capacity must be greater than 0');
+    }
+    this.capacity = Math.floor(capacity);
+    this.compare = compare;
+  }
+
+  push(v: T): void {
+    this.values.push(v);
+    if (this.values.length > this.capacity) {
+      this.values.shift();
+    }
+  }
+
+  toArray(): T[] {
+    return [...this.values];
+  }
+
+  clear(): void {
+    this.values.length = 0;
+  }
+
+  get max(): T | null {
+    if (this.values.length === 0) {
+      return null;
+    }
+    if (!this.compare) {
+      throw new Error('Comparator required for max()');
+    }
+    return this.values.reduce((acc, value) => (this.compare!(value, acc) > 0 ? value : acc), this.values[0]);
+  }
+
+  get min(): T | null {
+    if (this.values.length === 0) {
+      return null;
+    }
+    if (!this.compare) {
+      throw new Error('Comparator required for min()');
+    }
+    return this.values.reduce((acc, value) => (this.compare!(value, acc) < 0 ? value : acc), this.values[0]);
+  }
+}

ui/mobile/src/utils/urlValidator.ts

@@ -0,0 +1,25 @@
+const ALLOWED_PROTOCOLS = new Set(['http:', 'https:', 'ws:', 'wss:']);
+
+export interface UrlValidationResult {
+  valid: boolean;
+  error?: string;
+}
+
+export function validateServerUrl(url: string): UrlValidationResult {
+  if (typeof url !== 'string' || !url.trim()) {
+    return { valid: false, error: 'URL must be a non-empty string.' };
+  }
+
+  try {
+    const parsed = new URL(url);
+    if (!ALLOWED_PROTOCOLS.has(parsed.protocol)) {
+      return { valid: false, error: 'URL must use http, https, ws, or wss.' };
+    }
+    if (!parsed.host) {
+      return { valid: false, error: 'URL must include a host.' };
+    }
+    return { valid: true };
+  } catch {
+    return { valid: false, error: 'Invalid URL format.' };
+  }
+}