feat: offline SMS fallback for important notifications

断网时把验证码、来电用短信发到 iPhone：
- ConnectivityMonitor: NetworkCallback 监听在线状态
- CarrierDetector: SIM MCC+MNC 映射移动/联通/电信/广电
- CarrierBalanceQuery: 发免费查询短信拿套餐短信余量，解析回执
- SmsFallbackForwarder: 限频(5min)/余额(≤5挂起)/紧要性检查
- NotificationProcessor 拦截运营商回执(10086/10010/10001/10099)
- 设置页新增短信兜底卡片，首页余额耗尽警告

版本 1.3.0 → 1.4.0

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/java/com/a2i/forwarder/A2iApp.kt

@@ -1,8 +1,12 @@
 package com.a2i.forwarder
 
 import android.app.Application
+import com.a2i.forwarder.core.CarrierBalanceQuery
+import com.a2i.forwarder.core.CarrierDetector
+import com.a2i.forwarder.core.ConnectivityMonitor
 import com.a2i.forwarder.core.LogStore
 import com.a2i.forwarder.core.PhoneCallMonitor
+import com.a2i.forwarder.core.SmsFallbackForwarder
 import com.a2i.forwarder.store.AppRulesStore
 import com.a2i.forwarder.store.SettingsStore
 import kotlinx.coroutines.CoroutineScope
@@ -20,6 +24,12 @@ class A2iApp : Application() {
         private set
     lateinit var phoneCallMonitor: PhoneCallMonitor
         private set
+    lateinit var connectivityMonitor: ConnectivityMonitor
+        private set
+    lateinit var carrierBalanceQuery: CarrierBalanceQuery
+        private set
+    lateinit var smsForwarder: SmsFallbackForwarder
+        private set
 
     override fun onCreate() {
         super.onCreate()
@@ -29,6 +39,10 @@ class A2iApp : Application() {
         logStore = LogStore(this, appScope)
         phoneCallMonitor = PhoneCallMonitor(this)
         phoneCallMonitor.start()
+        connectivityMonitor = ConnectivityMonitor(this)
+        connectivityMonitor.start()
+        carrierBalanceQuery = CarrierBalanceQuery(this)
+        smsForwarder = SmsFallbackForwarder(this)
     }
 
     companion object {