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/command.rs

@@ -53,7 +53,7 @@ pub fn parse_command(text: &str) -> Command {
         "/lesson" if !arg1.is_empty() => Command::LessonCreate(arg1.to_string()),
         "/lesson" => Command::LessonList,
         "/login" if !arg1.is_empty() => Command::Login { provider: arg1.to_string() },
-        "/login" => Command::Login { provider: "openrouter".to_string() },
+        "/login" => Command::Login { provider: "zen".to_string() },
         _ => Command::Unknown(cmd.to_string()),
     }
 }