app: config: Use linkToDeath for PackageManager resilience (#29)

The previous implementation used `pingBinder()` to check the liveness of the PackageManager service on every call to `getPm()`. This polling approach introduces an unnecessary IPC round-trip overhead for every access.

This commit refactors the logic to use the canonical, event-driven pattern for handling remote service death by implementing `linkToDeath`.

A `DeathRecipient` is now registered with the binder upon the first connection. If the service process (`system_server`) dies for any reason, the `binderDied()` callback is automatically invoked by the system. This callback proactively clears the cached service instance, ensuring that the next call to `getPm()` will transparently re-establish a valid connection.

app/src/main/java/io/github/beakthoven/TrickyStoreOSS/core/config/Config.kt

@@ -7,6 +7,7 @@ package io.github.beakthoven.TrickyStoreOSS.core.config
 
 import android.content.pm.IPackageManager
 import android.os.FileObserver
+import android.os.IBinder
 import android.os.IInterface
 import android.os.ServiceManager
 import io.github.beakthoven.TrickyStoreOSS.CertificateHacker
@@ -127,10 +128,18 @@ object Config {
     }
 
     private var iPm: IPackageManager? = null
+    private val packageManagerDeathRecipient = object : IBinder.DeathRecipient {
+        override fun binderDied() {
+            (iPm as? IInterface)?.asBinder()?.unlinkToDeath(this, 0)
+            iPm = null
+        }
+    }
 
     fun getPm(): IPackageManager? {
-        if (iPm == null || (iPm as? IInterface)?.asBinder()?.pingBinder() != true) {
-            iPm = IPackageManager.Stub.asInterface(ServiceManager.getService("package"))
+        if (iPm == null) {
+            val binder = ServiceManager.getService("package")
+            binder.linkToDeath(packageManagerDeathRecipient, 0)
+            iPm = IPackageManager.Stub.asInterface(binder)
         }
         return iPm
     }
@@ -208,4 +217,4 @@ data class CustomPatchLevel(
     val vendor: String? = null,
     val boot: String? = null,
     val all: String? = null
-)
+)