feat(di): inject the phone client's ViewModels with Hilt

Replaces the hand-rolled ViewModelProvider.Factory in MainActivity with
constructor injection. No singleton is converted and no behaviour changes;
this only moves ViewModel construction into the graph so feature modules
can obtain their own ViewModels later.

MeshModule bridges the existing process-wide mesh instances into the graph.
Its bindings are deliberately unscoped: MeshServiceHolder is the source of
truth, it is shared with the foreground service, and it supports replacing
the mesh service after a panic clear. A @Singleton binding would pin the
first instance for the process lifetime and hand out a stale service after
a replacement.

ChatViewModel still resolves to a single activity-scoped instance, so the
unifiedMeshService.delegate assignment continues to reference the same
object it did before.

ApkDownloadViewModel is injected through its secondary constructor. Its
collaborators are internal types, and routing those through Dagger's
generated Java buys nothing; the primary constructor stays available so
tests can keep substituting fakes.

Verified: :app:assembleDebug, :wear:assembleDebug, and 591 unit tests pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NaZivRfLu7FdKjzVwwRjcc
(cherry picked from commit 33d6b36e220810c87595851ece7e9a63535c61b0)

app/src/main/java/com/bitchat/android/BitchatApplication.kt

@@ -4,10 +4,12 @@ import android.app.Application
 import com.bitchat.android.nostr.RelayDirectory
 import com.bitchat.android.ui.theme.ThemePreferenceManager
 import com.bitchat.android.net.ArtiTorManager
+import dagger.hilt.android.HiltAndroidApp
 
 /**
  * Main application class for bitchat Android
  */
+@HiltAndroidApp
 class BitchatApplication : Application() {
 
     override fun onCreate() {

app/src/main/java/com/bitchat/android/MainActivity.kt

@@ -16,7 +16,6 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.lifecycle.lifecycleScope
-import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.repeatOnLifecycle
 import androidx.lifecycle.Lifecycle
 import com.bitchat.android.mesh.BluetoothMeshService
@@ -46,9 +45,11 @@ import com.bitchat.android.ui.theme.BitchatTheme
 import com.bitchat.android.wifiaware.WifiAwareController
 import com.bitchat.android.nostr.PoWPreferenceManager
 import com.bitchat.android.services.VerificationService
+import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 
+@AndroidEntryPoint
 class MainActivity : OrientationAwareActivity() {
 
     private lateinit var permissionManager: PermissionManager
@@ -62,15 +63,8 @@ class MainActivity : OrientationAwareActivity() {
     private lateinit var unifiedMeshService: MeshService
     private val mainViewModel: MainViewModel by viewModels()
     private var pendingMeshForegroundServiceStart = false
-    private val chatViewModel: ChatViewModel by viewModels { 
-        object : ViewModelProvider.Factory {
-            override fun <T : androidx.lifecycle.ViewModel> create(modelClass: Class<T>): T {
-                @Suppress("UNCHECKED_CAST")
-                return ChatViewModel(application, meshService, unifiedMeshService) as T
-            }
-        }
-    }
-    
+    private val chatViewModel: ChatViewModel by viewModels()
+
     private val forceFinishReceiver = object : android.content.BroadcastReceiver() {
         override fun onReceive(context: android.content.Context, intent: android.content.Intent) {
             if (intent.action == com.bitchat.android.util.AppConstants.UI.ACTION_FORCE_FINISH) {

app/src/main/java/com/bitchat/android/MainViewModel.kt

@@ -7,9 +7,12 @@ import com.bitchat.android.onboarding.OnboardingState
 import com.bitchat.android.onboarding.BatteryOptimizationStatus
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.asStateFlow
+import javax.inject.Inject
 
-class MainViewModel : ViewModel() {
+@HiltViewModel
+class MainViewModel @Inject constructor() : ViewModel() {
 
     private val _onboardingState = MutableStateFlow(OnboardingState.CHECKING)
     val onboardingState: StateFlow<OnboardingState> = _onboardingState.asStateFlow()

app/src/main/java/com/bitchat/android/di/MeshModule.kt

@@ -0,0 +1,36 @@
+package com.bitchat.android.di
+
+import android.content.Context
+import com.bitchat.android.mesh.BluetoothMeshService
+import com.bitchat.android.mesh.MeshService
+import com.bitchat.android.service.MeshServiceHolder
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+
+/**
+ * Bridges the process-wide mesh instances into the injection graph.
+ *
+ * [MeshServiceHolder] remains the single source of truth: it is shared with the
+ * foreground service, it synchronises creation, and it supports replacing the
+ * mesh service after a panic clear. These bindings are therefore deliberately
+ * unscoped — each injection re-reads the holder. Caching them with @Singleton
+ * would pin the first instance for the process lifetime and hand out a stale
+ * mesh service after a replacement.
+ */
+@Module
+@InstallIn(SingletonComponent::class)
+object MeshModule {
+
+    @Provides
+    fun provideBluetoothMeshService(
+        @ApplicationContext context: Context
+    ): BluetoothMeshService = MeshServiceHolder.getOrCreate(context)
+
+    @Provides
+    fun provideMeshService(
+        @ApplicationContext context: Context
+    ): MeshService = MeshServiceHolder.getUnifiedOrCreate(context)
+}

app/src/main/java/com/bitchat/android/hotspot/HotspotActivity.kt

@@ -7,6 +7,7 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
+import dagger.hilt.android.AndroidEntryPoint
 import androidx.compose.animation.Crossfade
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
@@ -47,6 +48,7 @@ import java.io.File
  * Activity for managing Wi-Fi P2P hotspot for offline APK sharing.
  * Pure Compose implementation, no fragments.
  */
+@AndroidEntryPoint
 class HotspotActivity : ComponentActivity() {
 
     companion object {

app/src/main/java/com/bitchat/android/hotspot/HotspotViewModel.kt

@@ -7,6 +7,8 @@ import android.util.Log
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.bitchat.android.wifiaware.WifiAwareController
+import dagger.hilt.android.lifecycle.HiltViewModel
+import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -16,7 +18,10 @@ import java.io.File
 /**
  * ViewModel for managing hotspot state and lifecycle.
  */
-class HotspotViewModel(application: Application) : AndroidViewModel(application) {
+@HiltViewModel
+class HotspotViewModel @Inject constructor(
+    application: Application
+) : AndroidViewModel(application) {
 
     companion object {
         private const val TAG = "HotspotViewModel"

app/src/main/java/com/bitchat/android/ui/AboutSheet.kt

@@ -63,8 +63,8 @@ import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import androidx.lifecycle.viewmodel.compose.viewModel
 import com.bitchat.android.ui.theme.BitchatFontFamily
 import com.bitchat.android.R
 import com.bitchat.android.core.ui.component.button.CloseButton
@@ -617,7 +617,7 @@ fun AboutSheet(
                                     )
 
                                     // === Prepare App for Sharing Section ===
-                                    val apkViewModel: ApkDownloadViewModel = viewModel()
+                                    val apkViewModel: ApkDownloadViewModel = hiltViewModel()
                                     val apkUiState by apkViewModel.state.collectAsStateWithLifecycle()
                                     val apkStatus = apkUiState.apkStatus
                                     val releaseStatus = apkUiState.releaseStatus

app/src/main/java/com/bitchat/android/ui/ApkDownloadViewModel.kt

@@ -15,6 +15,8 @@ import com.bitchat.android.util.LatestReleaseProvider
 import com.bitchat.android.util.ShareableApkVariant
 import com.bitchat.android.util.UniversalApkManager
 import com.bitchat.android.util.WorkManagerApkDownloader
+import dagger.hilt.android.lifecycle.HiltViewModel
+import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.channels.Channel
@@ -151,6 +153,7 @@ sealed class ApkUiEffect {
  * ViewModel for APK download/status/share logic following MVI pattern.
  * UI sends [ApkUiEvent], observes [ApkUiState], and collects [ApkUiEffect].
  */
+@HiltViewModel
 class ApkDownloadViewModel internal constructor(
     application: Application,
     private val apkManager: UniversalApkManager,
@@ -158,6 +161,11 @@ class ApkDownloadViewModel internal constructor(
     private val latestReleaseProvider: LatestReleaseProvider
 ) : AndroidViewModel(application) {
 
+    // Hilt injects through this constructor rather than the primary one:
+    // UniversalApkManager's collaborators are internal, and routing internal
+    // Kotlin types through Dagger's generated Java buys nothing here. Tests
+    // keep using the primary constructor to substitute fakes.
+    @Inject
     constructor(application: Application) : this(
         application = application,
         apkManager = UniversalApkManager(application),

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -7,6 +7,8 @@ import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.bitchat.android.favorites.FavoritesChangeListener
 import com.bitchat.android.favorites.FavoritesPersistenceService
+import dagger.hilt.android.lifecycle.HiltViewModel
+import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -53,7 +55,8 @@ private data class ConversationLiveIdentityState(
  * Refactored ChatViewModel - Main coordinator for bitchat functionality
  * Delegates specific responsibilities to specialized managers while maintaining 100% iOS compatibility
  */
-class ChatViewModel(
+@HiltViewModel
+class ChatViewModel @Inject constructor(
     application: Application,
     initialMeshService: BluetoothMeshService,
     initialUnifiedMeshService: MeshService