Refactor scrolling methods in ScrollState to accept an amount parameter

- Updated `scroll_up` and `scroll_down` methods to take an `amount` parameter for more flexible scrolling.
- Removed the `AgentMode` enum and related methods from the types module to simplify state management.
- Modified `AppStateRest` to remove the `mode` field and adjusted related logic.
- Enhanced `run_subagent` to build tool definitions and handle API key resolution from configuration.
- Updated command parsing to reflect changes in login handling.
- Removed onboarding overlays and related logic from input handling and rendering.
- Improved status bar to reflect connection status and agent readiness.
- Adjusted workflow panel rendering to simplify phase status display.
- Refactored edit log initialization to load from disk if available.
- Updated settings structure to use a HashMap for API keys.
- Enhanced error handling in LlmClient for authentication issues.

src/app/state/misc.rs

@@ -35,17 +35,12 @@ impl ScrollState {
         }
     }
 
-    pub fn scroll_up(&mut self) {
-        if self.offset > 0 {
-            self.offset -= 1;
-        }
+    pub fn scroll_up(&mut self, amount: usize) {
+        self.offset = self.offset.saturating_add(amount);
     }
 
-    pub fn scroll_down(&mut self, total: usize) {
-        let max_offset = total.saturating_sub(self.max_visible);
-        if self.offset < max_offset {
-            self.offset += 1;
-        }
+    pub fn scroll_down(&mut self, amount: usize) {
+        self.offset = self.offset.saturating_sub(amount);
     }
 
     pub fn set_max_visible(&mut self, max: usize) {