fix: IME layout, message dedup, animation order, and overlay input positioning

- ChatScreen: restructure to Box overlay layout so only input area
  rises with IME, messages stay fixed. Add opaque background to input
  area. Use reverseLayout with newest-first animation order.
- OverlayContent: remove all manual IME detection — system forces
  adjust=pan on VoiceInteractionSession windows, so manual padding
  caused double offset. Let system handle IME naturally.
- ChatRepositoryImpl: add messageRemovals flow to clean up wrapping
  stream_end/response when review/multi_message items arrive later.
  Track lastResponseId in both stream_end and response handlers.
- ChatViewModel/OverlayViewModel: fix dedup to check by message ID
  only. Sort descending (newest first). Observe messageRemovals.
- NavGraph: keep all tabs composed with graphicsLayer alpha toggle —
  prevents ChatScreen destruction and re-render on tab switch.
- CyreneVoiceInteractionSession: defer configureWindow via post()
  to override system softInputMode flags.
- AndroidManifest: set windowSoftInputMode=adjustNothing on main
  activity.
- Add WebSocketKeepAliveService for background connection persistence.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/proguard-rules.pro

@@ -11,7 +11,14 @@
 -keepattributes Signature
 -keepattributes InnerClasses
 -keepattributes EnclosingMethod
+-keepattributes RuntimeVisibleAnnotations
+-keepattributes RuntimeVisibleParameterAnnotations
+-keepattributes AnnotationDefault
+-keepattributes KotlinMetadata
 -dontwarn kotlin.**
+-keep class kotlin.Metadata { *; }
+-keep class kotlin.coroutines.Continuation
+-keep class kotlinx.coroutines.** { *; }
 
 # --- Retrofit ---
 -keep class retrofit2.** { *; }
@@ -63,6 +70,28 @@
 # --- Keep PreferencesDataStore (Koin injects) ---
 -keep class top.yeij.cyrene.data.local.PreferencesDataStore { *; }
 
+# --- Keep utility classes (VoiceRecorder, RuntimeLog, etc. — injected by Koin) ---
+-keep class top.yeij.cyrene.util.** { *; }
+-keepclassmembers class top.yeij.cyrene.util.** { *; }
+
+# --- Keep voice/TTS/STT classes (injected by Koin into OverlayViewModel) ---
+-keep class top.yeij.cyrene.voice.** { *; }
+-keepclassmembers class top.yeij.cyrene.voice.** { *; }
+
+# --- Keep domain use cases (injected by Koin into ViewModels) ---
+-keep class top.yeij.cyrene.domain.usecase.** { *; }
+-keepclassmembers class top.yeij.cyrene.domain.usecase.** { *; }
+
+# --- Keep network interceptors and ApiService (Koin singletons) ---
+-keep class top.yeij.cyrene.data.remote.RetrofitClient { *; }
+-keep class top.yeij.cyrene.data.remote.ApiService { *; }
+-keep class top.yeij.cyrene.data.remote.AuthInterceptor { *; }
+-keep class top.yeij.cyrene.data.remote.DynamicUrlInterceptor { *; }
+-keep class top.yeij.cyrene.data.remote.TokenAuthenticator { *; }
+
+# --- Keep WebSocketService (injected into ChatRepositoryImpl) ---
+-keep class top.yeij.cyrene.service.WebSocketService { *; }
+
 # --- General AndroidX ---
 -keep class androidx.lifecycle.** { *; }
 -dontwarn androidx.lifecycle.**