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/runtime/commands.rs

@@ -43,6 +43,12 @@ pub fn apply_command(command: Command) -> Vec<Action> {
                 message: "transcript cleared".to_string(),
             }]
         }
+        Command::Login { provider } if provider.is_empty() => {
+            vec![Action::SystemNote {
+                kind: "error".to_string(),
+                message: "Usage: /login <provider>".to_string(),
+            }]
+        }
         Command::Login { provider } => {
             vec![Action::StartOAuth { provider }]
         }