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/app/state/rest.rs

@@ -106,6 +106,10 @@ impl AppStateRest {
         self.mode
     }
 
+    pub fn turn_in_flight(&self) -> bool {
+        self.turn_in_flight.lock().map(|g| *g).unwrap_or(false)
+    }
+
     pub fn set_mode(&mut self, mode: AgentMode) {
         self.mode = mode;
         self.dirty = true;