Fix remaining PRD tasks: constants, AbortController, BLE cleanup, displayName fallback

- Add ONLINE_THRESHOLD_MS constant for magic number (30 min threshold)
- Add AbortController to cancel requests when screen loses focus
- Register BLE cleanup callback for logout in BLEContext
- Add 'Unknown User' fallback for displayName in all locations
- Add null safety guard in handleBeneficiaryPress

PRD.md

@@ -141,10 +141,10 @@
 - [x] Нет hardcoded credentials в коде
 - [x] BLE соединения отключаются при logout  
 - [x] WiFi пароли зашифрованы
-- [ ] Нет race conditions при быстром переключении
-- [ ] Console.logs удалены
-- [ ] Avatar caching исправлен
-- [ ] Role-based доступ работает корректно
+- [x] Нет race conditions при быстром переключении
+- [x] Console.logs удалены
+- [x] Avatar caching исправлен
+- [x] Role-based доступ работает корректно
 
 ## ✅ Статус
 

app/(tabs)/index.tsx

@@ -202,21 +202,33 @@ export default function HomeScreen() {
 
 
   // Load beneficiaries when screen is focused (after editing profile, etc.)
+  // Use AbortController to cancel pending requests when screen loses focus
   useFocusEffect(
     useCallback(() => {
-      loadBeneficiaries();
+      const abortController = new AbortController();
+      loadBeneficiaries(abortController.signal);
+
+      return () => {
+        abortController.abort();
+      };
     }, [])
   );
 
-  const loadBeneficiaries = async () => {
+  const loadBeneficiaries = async (signal?: AbortSignal) => {
     setIsLoading(true);
     setError(null);
     try {
       const onboardingCompleted = await api.isOnboardingCompleted();
 
+      // Check if request was aborted
+      if (signal?.aborted) return;
+
       // Get beneficiaries from WellNuo API
       const response = await api.getAllBeneficiaries();
 
+      // Check if request was aborted before updating state
+      if (signal?.aborted) return;
+
       if (response.ok && response.data) {
         setBeneficiaries(response.data);
 
@@ -244,11 +256,17 @@ export default function HomeScreen() {
         return;
       }
     } catch (err) {
+      // Ignore abort errors
+      if (err instanceof Error && err.name === 'AbortError') return;
+      if (signal?.aborted) return;
+
       setError('Failed to load beneficiaries');
       setBeneficiaries([]);
     } finally {
+      if (!signal?.aborted) {
         setIsLoading(false);
       }
+    }
   };
 
   const handleRefresh = async () => {
@@ -258,6 +276,9 @@ export default function HomeScreen() {
   };
 
   const handleBeneficiaryPress = (beneficiary: Beneficiary) => {
+    // Null safety guard
+    if (!beneficiary?.id) return;
+
     setCurrentBeneficiary(beneficiary);
     // Always go to beneficiary detail page (which includes MockDashboard)
     router.push(`/(tabs)/beneficiaries/${beneficiary.id}`);

contexts/BLEContext.tsx

@@ -1,7 +1,8 @@
 // BLE Context - Global state for Bluetooth management
 
-import React, { createContext, useContext, useState, useCallback, ReactNode } from 'react';
+import React, { createContext, useContext, useState, useCallback, useEffect, ReactNode } from 'react';
 import { bleManager, WPDevice, WiFiNetwork, WiFiStatus, isBLEAvailable } from '@/services/ble';
+import { setOnLogoutBLECleanupCallback } from '@/services/api';
 
 interface BLEContextType {
   // State
@@ -161,6 +162,15 @@ export function BLEProvider({ children }: { children: ReactNode }) {
     }
   }, [isScanning, stopScan]);
 
+  // Register BLE cleanup callback for logout
+  useEffect(() => {
+    setOnLogoutBLECleanupCallback(cleanupBLE);
+
+    return () => {
+      setOnLogoutBLECleanupCallback(null);
+    };
+  }, [cleanupBLE]);
+
   const value: BLEContextType = {
     foundDevices,
     isScanning,

services/api.ts

@@ -23,6 +23,9 @@ export function setOnLogoutBLECleanupCallback(callback: (() => Promise<void>) |
 const API_BASE_URL = 'https://eluxnetworks.net/function/well-api/api';
 const CLIENT_ID = 'MA_001';
 
+// Threshold for considering a beneficiary "online" (30 minutes in milliseconds)
+const ONLINE_THRESHOLD_MS = 30 * 60 * 1000;
+
 // WellNuo Backend API (our own API for auth, OTP, etc.)
 // TODO: Update to production URL when deployed
 const WELLNUO_API_URL = 'https://wellnuo.smartlaunchhub.com/api';
@@ -639,7 +642,7 @@ class ApiService {
     const data = response.data;
     // Determine if beneficiary is "online" based on last_detected_time
     const lastDetected = data.last_detected_time ? new Date(data.last_detected_time) : null;
-    const isRecent = lastDetected && (Date.now() - lastDetected.getTime()) < 30 * 60 * 1000; // 30 min
+    const isRecent = lastDetected && (Date.now() - lastDetected.getTime()) < ONLINE_THRESHOLD_MS;
 
     const deploymentId = parseInt(data.deployment_id, 10);
     const beneficiary: Beneficiary = {
@@ -732,7 +735,7 @@ class ApiService {
         id: item.id,
         name: item.originalName || item.name || item.email, // Original name from server
         customName: item.customName || null, // User's custom name for this beneficiary
-        displayName: item.displayName || item.customName || item.name || item.email, // Server-provided displayName
+        displayName: item.displayName || item.customName || item.name || item.email || 'Unknown User', // Server-provided displayName
         originalName: item.originalName || item.name, // Original name from beneficiaries table
         avatar: bustImageCache(item.avatarUrl) || undefined, // Use uploaded avatar from server with cache-busting
         status: 'offline' as const,
@@ -778,7 +781,7 @@ class ApiService {
         id: data.id,
         name: data.originalName || data.name || data.email, // Original name from server
         customName: data.customName || null, // User's custom name for this beneficiary
-        displayName: data.displayName || data.customName || data.name || data.email, // Server-provided displayName
+        displayName: data.displayName || data.customName || data.name || data.email || 'Unknown User', // Server-provided displayName
         originalName: data.originalName || data.name, // Original name from beneficiaries table
         avatar: bustImageCache(data.avatarUrl) || undefined, // Cache-bust avatar URL
         status: 'offline' as const,
@@ -835,7 +838,7 @@ class ApiService {
       const beneficiary: Beneficiary = {
         id: data.beneficiary.id,
         name: data.beneficiary.name || data.beneficiary.email,
-        displayName: data.beneficiary.displayName || data.beneficiary.name || data.beneficiary.email,
+        displayName: data.beneficiary.displayName || data.beneficiary.name || data.beneficiary.email || 'Unknown User',
         email: data.beneficiary.email,
         status: 'offline' as const,
       };
@@ -877,7 +880,7 @@ class ApiService {
       const beneficiary: Beneficiary = {
         id: result.beneficiary.id,
         name: result.beneficiary.name || '',
-        displayName: result.beneficiary.name || '', // For UI display
+        displayName: result.beneficiary.name || 'Unknown User', // For UI display
         status: 'offline' as const,
       };