feat: add terminal detachment functionality

implement terminal cleanup when closing tabs or unmounting component

remove unused actionRunner prop across components

delete unused file-watcher utility

app/components/workbench/terminal/Terminal.tsx

@@ -10,6 +10,7 @@ const logger = createScopedLogger('Terminal');
 
 export interface TerminalRef {
   reloadStyles: () => void;
+  getTerminal: () => XTerm | undefined;
 }
 
 export interface TerminalProps {
@@ -80,6 +81,9 @@ export const Terminal = memo(
             const terminal = terminalRef.current!;
             terminal.options.theme = getTerminalTheme(readonly ? { cursor: '#00000000' } : {});
           },
+          getTerminal: () => {
+            return terminalRef.current;
+          },
         };
       }, []);