Refactor API integration and enhance command handling

- Removed unused modules and updated module paths for clarity.
- Added autocomplete functionality for command input in InputState.
- Updated AppStateRest to include a method for checking if a turn is in flight.
- Refactored subagent engine to use new API client structure.
- Changed default provider from "openrouter" to "zen" with updated API keys and models.
- Implemented tests for memory management and edit log functionalities.
- Enhanced error handling in API requests and improved response parsing.
- Updated UI components to reflect new API provider and status indicators.

src/controller/input.rs

@@ -89,6 +89,10 @@ pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
             }
         }
         KeyCode::Tab => {
+            if state.input.buffer.starts_with('/') {
+                state.input.tab_complete();
+                state.dirty = true;
+            }
             Vec::new()
         }
         KeyCode::Char('l') if key.modifiers.contains(KeyModifiers::CONTROL) => {