test(lists): improve test coverage and extract list ID parsing

- Extract extractListId to src/lib/extract-list-id.ts with proper tests
- Add json-full/includeRaw test for list timeline
- Add 404 retry tests for getOwnedLists and getListMemberships
- Add tests for skipping invalid list entries and missing owner handling
- Use shared TwitterClientPrivate type from fixtures

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

tests/cli.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest';
 import { extractBookmarkFolderId } from '../src/lib/extract-bookmark-folder-id.js';
+import { extractListId } from '../src/lib/extract-list-id.js';
 import { extractTweetId } from '../src/lib/extract-tweet-id.js';
 
 describe('CLI utilities', () => {
@@ -56,4 +57,46 @@ describe('CLI utilities', () => {
       expect(extractBookmarkFolderId(url)).toBeNull();
     });
   });
+
+  describe('extractListId', () => {
+    it('should extract ID from x.com list URL', () => {
+      const url = 'https://x.com/i/lists/1234567890123456789';
+      expect(extractListId(url)).toBe('1234567890123456789');
+    });
+
+    it('should extract ID from twitter.com list URL', () => {
+      const url = 'https://twitter.com/i/lists/1234567890123456789';
+      expect(extractListId(url)).toBe('1234567890123456789');
+    });
+
+    it('should extract ID from URL with query params', () => {
+      const url = 'https://x.com/i/lists/1234567890123456789?s=20';
+      expect(extractListId(url)).toBe('1234567890123456789');
+    });
+
+    it('should accept a numeric ID as-is', () => {
+      const id = '1234567890123456789';
+      expect(extractListId(id)).toBe('1234567890123456789');
+    });
+
+    it('should return null for invalid values', () => {
+      expect(extractListId('not-an-id')).toBeNull();
+    });
+
+    it('should return null for empty string', () => {
+      expect(extractListId('')).toBeNull();
+    });
+
+    it('should return null for whitespace-only string', () => {
+      expect(extractListId('   ')).toBeNull();
+    });
+
+    it('should return null for short numeric IDs', () => {
+      expect(extractListId('1234')).toBeNull();
+    });
+
+    it('should trim whitespace from input', () => {
+      expect(extractListId('  1234567890123456789  ')).toBe('1234567890123456789');
+    });
+  });
 });