refactor(feedback): use shared toError + extend ValidationError

Per Hweinstock's review:

- handleFeedback / useFeedbackFlow: replace the local
  `err instanceof Error ? err : new Error(String(err))` pattern with
  `toError(err)` from src/lib/errors/types.ts.
- FeedbackValidationError: extend `ValidationError` from
  src/lib/errors/types.ts so the shared error classification helpers
  treat it as a user error, which means telemetry's
  classifyError(err)/isUserError(err) will set error_source: 'user'
  on failure metrics for invalid screenshots / empty messages.

Author: tejaskash

src/cli/commands/feedback/action.ts

@@ -1,3 +1,4 @@
+import { toError } from '../../../lib/errors/types';
 import { submitFeedback } from '../../operations/feedback';
 import type { FeedbackSubmissionResult } from '../../operations/feedback';
 import { promptForConsent } from './consent-prompt';
@@ -23,6 +24,6 @@ export async function handleFeedback(message: string, options: FeedbackOptions):
     });
     return { kind: 'submitted', result };
   } catch (err) {
-    return { kind: 'error', error: err instanceof Error ? err : new Error(String(err)) };
+    return { kind: 'error', error: toError(err) };
   }
 }

src/cli/operations/feedback/submit-feedback.ts

@@ -1,3 +1,4 @@
+import { ValidationError } from '../../../lib/errors/types';
 import { PACKAGE_VERSION } from '../../constants';
 import { fetchPresignedUrl, submitForm, uploadFileToS3 } from './aperture-client';
 import { buildFeedbackPayload, buildUserAgent } from './build-payload';
@@ -14,10 +15,15 @@ import * as fs from 'node:fs/promises';
 import * as os from 'node:os';
 import * as path from 'node:path';
 
-export class FeedbackValidationError extends Error {
+/**
+ * Thrown for any user-supplied input the feedback command refuses to send to
+ * Aperture (empty/oversized message, missing/oversized/wrong-type screenshot).
+ * Extends the shared `ValidationError` so telemetry classifies it as a user
+ * error rather than a service/client failure.
+ */
+export class FeedbackValidationError extends ValidationError {
   constructor(message: string) {
     super(message);
-    this.name = 'FeedbackValidationError';
   }
 }
 

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

@@ -1,3 +1,4 @@
+import { toError } from '../../../../lib/errors/types';
 import { submitFeedback, validateFeedbackMessage, validateScreenshotPath } from '../../../operations/feedback';
 import type { FeedbackSubmissionResult } from '../../../operations/feedback';
 import { withCommandRunTelemetry } from '../../../telemetry/cli-command-run';
@@ -92,7 +93,7 @@ export function useFeedbackFlow(options: UseFeedbackFlowOptions = {}) {
           });
           return { success: true, submission };
         } catch (err) {
-          return { success: false, error: err instanceof Error ? err : new Error(String(err)) };
+          return { success: false, error: toError(err) };
         }
       }
     );