feat(cli): mentions target user

tests/normalize-handle.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from 'vitest';
+import { normalizeHandle } from '../src/lib/normalize-handle.js';
+
+describe('normalizeHandle', () => {
+  it('accepts bare handle', () => {
+    expect(normalizeHandle('steipete')).toBe('steipete');
+  });
+
+  it('accepts @handle and trims whitespace', () => {
+    expect(normalizeHandle('  @steipete  ')).toBe('steipete');
+  });
+
+  it('rejects empty input', () => {
+    expect(normalizeHandle('')).toBeNull();
+    expect(normalizeHandle('   ')).toBeNull();
+    expect(normalizeHandle(null)).toBeNull();
+  });
+
+  it('rejects invalid characters and too-long handles', () => {
+    expect(normalizeHandle('@stei-pete')).toBeNull();
+    expect(normalizeHandle('@steipete!')).toBeNull();
+    expect(normalizeHandle('a'.repeat(16))).toBeNull();
+  });
+});