feat: phone call monitoring + SMS sent filter + icon prefix default

- 新增 PhoneCallMonitor：通过轮询 getCallState() 感知来电/未接
  （绕过 MIUI 对系统电话通知的限制，需 READ_PHONE_STATE 权限）
- 短信仅收不发：过滤"发送中"/"已发送"等关键词
- 图标 URL 前缀默认值：GitHub raw 图床
- 从黑名单移除 com.android.phone/com.android.incallui
- 默认黑名单新增三星剪贴板/GMS 等噪音包名
- 版本 1.2.0 → 1.3.0

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

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

@@ -2,6 +2,7 @@ package com.a2i.forwarder
 
 import android.app.Application
 import com.a2i.forwarder.core.LogStore
+import com.a2i.forwarder.core.PhoneCallMonitor
 import com.a2i.forwarder.store.AppRulesStore
 import com.a2i.forwarder.store.SettingsStore
 import kotlinx.coroutines.CoroutineScope
@@ -17,6 +18,8 @@ class A2iApp : Application() {
         private set
     lateinit var logStore: LogStore
         private set
+    lateinit var phoneCallMonitor: PhoneCallMonitor
+        private set
 
     override fun onCreate() {
         super.onCreate()
@@ -24,6 +27,8 @@ class A2iApp : Application() {
         settings = SettingsStore(this, appScope)
         appRules = AppRulesStore(this, appScope)
         logStore = LogStore(this, appScope)
+        phoneCallMonitor = PhoneCallMonitor(this)
+        phoneCallMonitor.start()
     }
 
     companion object {