diff --git a/wear/build.gradle.kts b/wear/build.gradle.kts
index 16b73259..12cf5534 100644
--- a/wear/build.gradle.kts
+++ b/wear/build.gradle.kts
@@ -30,6 +30,9 @@ android {
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
+            // Sign with the debug key so release builds can be installed over the
+            // debug app during development (same signature = seamless upgrade).
+            signingConfig = signingConfigs.getByName("debug")
         }
     }
 
diff --git a/wear/proguard-rules.pro b/wear/proguard-rules.pro
new file mode 100644
index 00000000..001b0a09
--- /dev/null
+++ b/wear/proguard-rules.pro
@@ -0,0 +1,13 @@
+# Gson reflection targets in the shared bitchat sources (persisted state payloads).
+-keep class com.bitchat.android.favorites.** { *; }
+-keep class com.bitchat.android.services.SeenMessageStore$* { *; }
+-keepclassmembers class * {
+    @com.google.gson.annotations.SerializedName <fields>;
+}
+
+# Kotlin metadata needed by reflection-based serialization.
+-keepattributes Signature, InnerClasses, EnclosingMethod
+
+# Tink references JSR-305 annotations not present on Android.
+-dontwarn javax.annotation.Nullable
+-dontwarn javax.annotation.concurrent.GuardedBy
diff --git a/wear/src/main/java/com/bitchat/watch/ui/ChatScreen.kt b/wear/src/main/java/com/bitchat/watch/ui/ChatScreen.kt
index b9aa013d..7ead1fc4 100644
--- a/wear/src/main/java/com/bitchat/watch/ui/ChatScreen.kt
+++ b/wear/src/main/java/com/bitchat/watch/ui/ChatScreen.kt
@@ -221,10 +221,12 @@ fun MessageItem(
                 onOpen = onOpenImage
             )
             BitchatMessageType.Audio -> VoiceNoteItem(path = message.content.trim())
-            BitchatMessageType.File -> FileMessageChip(
-                name = File(message.content.trim()).name,
-                sizeBytes = File(message.content.trim()).length()
-            )
+            BitchatMessageType.File -> {
+                val path = message.content.trim()
+                val file = remember(path) { File(path) }
+                val sizeBytes = remember(path) { file.length() }
+                FileMessageChip(name = file.name, sizeBytes = sizeBytes)
+            }
             BitchatMessageType.Message -> Text(
                 text = message.content,
                 style = ChatVisualTokens.MessageBodyStyle,
@@ -235,5 +237,6 @@ fun MessageItem(
     }
 }
 
-private fun formatTime(date: Date): String =
-    SimpleDateFormat("HH:mm", Locale.getDefault()).format(date)
+private val timeFormat = SimpleDateFormat("HH:mm", Locale.getDefault())
+
+private fun formatTime(date: Date): String = timeFormat.format(date)