feat: configurable chat history scrollback

src-tauri/src/types.rs

@@ -573,6 +573,11 @@ pub(crate) struct AppSettings {
         rename = "showMessageFilePath"
     )]
     pub(crate) show_message_file_path: bool,
+    #[serde(
+        default = "default_chat_history_scrollback_items",
+        rename = "chatHistoryScrollbackItems"
+    )]
+    pub(crate) chat_history_scrollback_items: Option<u32>,
     #[serde(default, rename = "threadTitleAutogenerationEnabled")]
     pub(crate) thread_title_autogeneration_enabled: bool,
     #[serde(default = "default_ui_font_family", rename = "uiFontFamily")]
@@ -760,6 +765,10 @@ fn default_show_message_file_path() -> bool {
     true
 }
 
+fn default_chat_history_scrollback_items() -> Option<u32> {
+    Some(200)
+}
+
 fn default_ui_font_family() -> String {
     "system-ui, -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, \"Helvetica Neue\", Arial, sans-serif".to_string()
 }
@@ -1187,6 +1196,7 @@ impl Default for AppSettings {
             theme: default_theme(),
             usage_show_remaining: default_usage_show_remaining(),
             show_message_file_path: default_show_message_file_path(),
+            chat_history_scrollback_items: default_chat_history_scrollback_items(),
             thread_title_autogeneration_enabled: false,
             ui_font_family: default_ui_font_family(),
             code_font_family: default_code_font_family(),
@@ -1350,6 +1360,7 @@ mod tests {
         assert_eq!(settings.theme, "system");
         assert!(!settings.usage_show_remaining);
         assert!(settings.show_message_file_path);
+        assert_eq!(settings.chat_history_scrollback_items, Some(200));
         assert!(!settings.thread_title_autogeneration_enabled);
         assert!(settings.ui_font_family.contains("system-ui"));
         assert!(settings.code_font_family.contains("ui-monospace"));

src/App.tsx

@@ -575,6 +575,9 @@ function MainApp() {
     reviewDeliveryMode: appSettings.reviewDeliveryMode,
     steerEnabled: appSettings.steerEnabled,
     threadTitleAutogenerationEnabled: appSettings.threadTitleAutogenerationEnabled,
+    chatHistoryScrollbackItems: appSettingsLoading
+      ? null
+      : appSettings.chatHistoryScrollbackItems,
     customPrompts: prompts,
     onMessageActivity: handleThreadMessageActivity,
     threadSortKey: threadListSortKey,