Fix performance issue by caching typing effect settings in ChatUiState (#329)

* Fix performance issue by caching typing effect settings in ChatUiState

- Moved `AuthManager.isTypingEffectEnabled()` and `AuthManager.getTypingEffectDelayMs()` out of `ChatScreen.kt` recomposition loops.
- Stored `typingEffectEnabled` and `typingEffectDelayMs` in `ChatUiState`.
- Added `refreshSettings()` to `ChatViewModel` to fetch settings upon initialization and on returning to the chat screen (ON_START).
- Prevents expensive EncryptedSharedPreferences XML decryption occurring on every message per token stream update.

Fixes #269

* Fix performance issue by caching typing effect settings in ChatUiState

- Moved `AuthManager.isTypingEffectEnabled()` and `AuthManager.getTypingEffectDelayMs()` out of `ChatScreen.kt` recomposition loops.
- Stored `typingEffectEnabled` and `typingEffectDelayMs` in `ChatUiState`.
- Added `refreshSettings()` to `ChatViewModel` to fetch settings upon initialization and on returning to the chat screen (ON_START).
- Prevents expensive EncryptedSharedPreferences XML decryption occurring on every message per token stream update.
- Fixed `ChatViewModelTest` missing mocks for `AuthManager.isTypingEffectEnabled()` and `AuthManager.getTypingEffectDelayMs()`.
- Fixed ktlint unused import and max line length violations.

Fixes #269

app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt

@@ -64,6 +64,8 @@ class ChatViewModelTest {
         mockConnectionStatus.value = ConnectionStatus.DISCONNECTED
 
         every { AuthManager.getToken() } returns "test-token"
+        every { AuthManager.isTypingEffectEnabled() } returns true
+        every { AuthManager.getTypingEffectDelayMs() } returns 30
         every { HermesWsClient.events } returns mockEventsFlow
         every { HermesWsClient.connectionStatus } returns mockConnectionStatus
         every { HermesWsClient.connect() } returns Unit