feat(chat): add configurable message stats (#1134)

app/src/main/java/com/m57/hermescontrol/data/config/ServerStoreState.kt

@@ -24,6 +24,10 @@ data class ServerStoreState(
     val typingEffectEnabled: Boolean = true,
     val typingEffectDelayMs: Int = 30,
     val chatFontScale: Float = 1.0f,
+    val messageStatsEnabled: Boolean = false,
+    val showUserMessageTokens: Boolean = true,
+    val showAssistantMessageTokens: Boolean = true,
+    val showTokensPerSecond: Boolean = true,
     // App display language. "system" = follow device locale; otherwise a BCP-47
     // language code such as "en" or "ko". Applied via ContextWrapper in MainActivity.
     val appLanguage: String = "system",

app/src/main/java/com/m57/hermescontrol/data/local/AuthManager.kt

@@ -713,6 +713,32 @@ object AuthManager {
         serverStore.update { it.copy(typingEffectDelayMs = delayMs) }
     }
 
+    // ── Message stats ───────────────────────────────────────────────────
+
+    fun isMessageStatsEnabled(): Boolean = serverStore.getLatestState().messageStatsEnabled
+
+    fun setMessageStatsEnabled(enabled: Boolean) {
+        serverStore.update { it.copy(messageStatsEnabled = enabled) }
+    }
+
+    fun isUserMessageTokensEnabled(): Boolean = serverStore.getLatestState().showUserMessageTokens
+
+    fun setUserMessageTokensEnabled(enabled: Boolean) {
+        serverStore.update { it.copy(showUserMessageTokens = enabled) }
+    }
+
+    fun isAssistantMessageTokensEnabled(): Boolean = serverStore.getLatestState().showAssistantMessageTokens
+
+    fun setAssistantMessageTokensEnabled(enabled: Boolean) {
+        serverStore.update { it.copy(showAssistantMessageTokens = enabled) }
+    }
+
+    fun isTokensPerSecondEnabled(): Boolean = serverStore.getLatestState().showTokensPerSecond
+
+    fun setTokensPerSecondEnabled(enabled: Boolean) {
+        serverStore.update { it.copy(showTokensPerSecond = enabled) }
+    }
+
     // ── Chat Font Scale (issue #1004) ───────────────────────────────────
 
     fun getChatFontScale(): Float = serverStore.getLatestState().chatFontScale