fix(feedback): preserve full Error object through outcome and state

Per Hweinstock's review feedback. Was stringifying errors to .message at
the boundary in handleFeedback and useFeedbackFlow, which discarded the
stack/cause. Keeping the Error around lets callers retain that info and
narrow with instanceof when they want; we still pull .message at the
final UI render boundary.

Author: tejaskash

src/cli/commands/feedback/action.ts

@@ -7,7 +7,7 @@ export type FeedbackOutcome =
   | { kind: 'submitted'; result: FeedbackSubmissionResult }
   | { kind: 'declined' }
   | { kind: 'no-tty' }
-  | { kind: 'error'; error: string };
+  | { kind: 'error'; error: Error };
 
 export async function handleFeedback(message: string, options: FeedbackOptions): Promise<FeedbackOutcome> {
   const consent = await promptForConsent();
@@ -23,7 +23,6 @@ export async function handleFeedback(message: string, options: FeedbackOptions):
     });
     return { kind: 'submitted', result };
   } catch (err) {
-    const error = err instanceof Error ? err.message : String(err);
-    return { kind: 'error', error };
+    return { kind: 'error', error: err instanceof Error ? err : new Error(String(err)) };
   }
 }

src/cli/commands/feedback/command.tsx

@@ -49,7 +49,7 @@ export const registerFeedback = (program: Command) => {
             throw new Error('Feedback consent must be confirmed interactively. Re-run agentcore feedback in a TTY.');
           }
           if (outcome.kind === 'error') {
-            throw new Error(outcome.error);
+            throw outcome.error;
           }
           if (outcome.kind === 'declined') {
             if (options.json) {

src/cli/tui/screens/feedback/FeedbackScreen.tsx

@@ -154,5 +154,7 @@ export function FeedbackScreen({ initialScreenshot, onExit }: FeedbackScreenProp
     );
   }
 
-  return <ErrorPrompt message="Failed to submit feedback." detail={state.error} onBack={retry} onExit={onExit} />;
+  return (
+    <ErrorPrompt message="Failed to submit feedback." detail={state.error?.message} onBack={retry} onExit={onExit} />
+  );
 }

src/cli/tui/screens/feedback/__tests__/useFeedbackFlow.test.tsx

@@ -43,7 +43,7 @@ const Harness = React.forwardRef<HarnessHandle, HarnessProps>((props, ref) => {
     <Text>
       phase:{flow.state.phase} message:{flow.state.message || '<empty>'} screenshot:
       {flow.state.screenshotPath ?? '<none>'} error:
-      {flow.state.error ?? '<none>'} inputError:{flow.state.inputError ?? '<none>'}
+      {flow.state.error?.message ?? '<none>'} inputError:{flow.state.inputError ?? '<none>'}
     </Text>
   );
 });
@@ -178,7 +178,7 @@ describe('useFeedbackFlow', () => {
     act(() => ref.current!.flow.confirmConsent());
     await flushAsync();
     expect(ref.current!.flow.state.phase).toBe('error');
-    expect(ref.current!.flow.state.error).toBe('HTTP 500');
+    expect(ref.current!.flow.state.error?.message).toBe('HTTP 500');
 
     act(() => ref.current!.flow.retry());
     await flushAsync();

src/cli/tui/screens/feedback/useFeedbackFlow.ts

@@ -17,8 +17,8 @@ export interface FeedbackState {
   message: string;
   screenshotPath?: string;
   result?: FeedbackSubmissionResult;
-  /** Submission failure detail, shown on the 'error' phase. */
-  error?: string;
+  /** Submission failure detail, shown on the 'error' phase. Preserved as Error so callers retain stack/cause. */
+  error?: Error;
   /** Inline validation error shown on the current input phase. */
   inputError?: string;
 }
@@ -110,7 +110,7 @@ export function useFeedbackFlow(options: UseFeedbackFlowOptions = {}) {
     if (result.success) {
       setState(prev => ({ ...prev, phase: 'success', result: result.submission }));
     } else {
-      setState(prev => ({ ...prev, phase: 'error', error: result.error.message }));
+      setState(prev => ({ ...prev, phase: 'error', error: result.error }));
     }
   }, [onSubmit, state.message, state.screenshotPath]);