Reset ViewModels on logout/account switch

This commit introduces a `ResetModel()` function to `AgentViewModel` and `MineAgentViewModel` to clear their state.

This function is now called in `ResourceCleanupManager` and `AppState` during logout or when switching accounts to ensure that data from the previous session is not retained.

Additionally, the search and group name input fields in `CreateGroupChatScreen` are now single-line.

app/src/main/java/com/aiosman/ravenow/ui/group/CreateGroupChatScreen.kt

@@ -197,6 +197,7 @@ fun CreateGroupChatScreen() {
                         fontSize = 14.sp
                     ),
                     modifier = Modifier.weight(1f),
+                    singleLine = true,
                     decorationBox = { innerTextField ->
                         Box {
                             if (searchText.text.isEmpty()) {
@@ -277,6 +278,7 @@ fun CreateGroupChatScreen() {
                     ),
                     modifier = Modifier
                         .weight(1f),
+                    singleLine = true,
                     decorationBox = { innerTextField ->
                         Box(Modifier.fillMaxWidth()) {
                             if (groupName.text.isEmpty()) {