Fix: Critical crash and security vulnerabilities

- Fix generateEmbeddings() NPE: elvis operator result was never used,
  causing guaranteed NullPointerException when service not bound
- Security: Set all non-launcher activities to exported="false" to
  prevent other apps from launching internal activities
- Security: Disable cleartext HTTP traffic globally, only allow for
  localhost (development). Remove user certificate trust.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mithun50

ai-module/src/main/java/com/nano/ai_module/workers/ModelManager.kt

@@ -501,11 +501,11 @@ object ModelManager {
 
     //region Embedding-Generation
     suspend fun generateEmbeddings(input: String): FloatArray = withContext(Dispatchers.IO) {
-        service ?: {
+        val svc = service ?: run {
             Log.e(TAG, "Service not bound")
-            FloatArray(0)
+            return@withContext FloatArray(0)
         }
-        return@withContext service!!.embed(input)
+        return@withContext svc.embed(input)
     }
     //endregion
 

app/src/main/AndroidManifest.xml

@@ -41,7 +41,7 @@
 
         <activity
             android:name=".activity.PluginHubActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -50,7 +50,7 @@
 
         <activity
             android:name=".activity.SetupActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -60,7 +60,7 @@
 
         <activity
             android:name=".activity.GgufPickerActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -69,7 +69,7 @@
 
         <activity
             android:name=".activity.UserDataActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -79,7 +79,7 @@
 
         <activity
             android:name=".activity.ModelPropEditorActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -88,7 +88,7 @@
 
         <activity
             android:name=".activity.ModelLoadingActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -98,7 +98,7 @@
 
         <activity
             android:name=".activity.ModelActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -107,7 +107,7 @@
 
         <activity
             android:name=".activity.DatahubActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -116,7 +116,7 @@
 
         <activity
             android:name=".activity.TempActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -125,7 +125,7 @@
 
         <activity
             android:name=".activity.LoggerActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">
@@ -134,7 +134,7 @@
 
         <activity
             android:name=".activity.ScrapActivity"
-            android:exported="true"
+            android:exported="false"
             android:launchMode="singleTask"
             android:theme="@style/Theme.NanoAI"
             android:windowSoftInputMode="adjustResize">

app/src/main/res/xml/network_security_config.xml

@@ -1,13 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <network-security-config>
-    <base-config cleartextTrafficPermitted="true">
+    <base-config cleartextTrafficPermitted="false">
         <trust-anchors>
             <certificates src="system" />
-            <certificates src="user" />
         </trust-anchors>
     </base-config>
+    <!-- Allow cleartext only for localhost (local development/testing) -->
     <domain-config cleartextTrafficPermitted="true">
         <domain includeSubdomains="true">localhost</domain>
         <domain includeSubdomains="true">127.0.0.1</domain>
+        <domain includeSubdomains="true">10.0.2.2</domain>
     </domain-config>
 </network-security-config>