docs: fix code size numbers in comparison matrix

Verified against actual source:
- Claude Code: ~100K (est) → ~512K (actual, 1884 TS/TSX files)
- Gemini CLI: ~50K → ~550K (actual)
- Qwen Code: ~50K → ~439K (actual)
- Codex CLI: 619K unchanged (already verified from Rust source)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: wenshao

docs/comparison/qwen-code-codex-improvements.md

@@ -399,7 +399,7 @@
 | 能力 | Codex CLI | Claude Code | Gemini CLI | Qwen Code |
 |------|----------|-------------|-----------|-----------|
 | **技术栈** | Rust 原生 | TypeScript/Rust | TypeScript | TypeScript |
-| **代码规模** | 619,458 行 | ~100,000 行（估） | ~50,000 行 | ~50,000 行 |
+| **代码规模** | 619,458 行 | ~512,000 行 | ~550,000 行 | ~439,000 行 |
 | **默认沙箱** | ✅ 3 平台原生 | 可选 | 可选 | 可选（Docker/Podman/Seatbelt） |
 | **网络隔离** | ✅ 默认阻断 | 可选 | 无 | ❌ |
 | **Feature Flag** | 52 运行时 | 22 编译时 | 无 | ❌ |