feat: 全面清理类型错误 — tsc 零错误，any 标注全部消除

- 修复所有 33 个原始 tsc 编译错误（ink JSX 声明、类型不匹配、null check 等）
- 清理 176 处 `: any` 类型标注，全部替换为具体推断类型
- 修复清理过程中引入的 41 个回归错误
- 最终结果：0 tsc 错误，0 个非注释 any 标注
- Build 验证通过（25.75MB bundle）

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/commands/assistant/assistant.ts

@@ -1,4 +1,11 @@
 // Auto-generated stub — replace with real implementation
+import type React from 'react';
+
 export {};
-export const NewInstallWizard: any = (() => {}) as any;
-export const computeDefaultInstallDir: any = (() => {}) as any;
+export const NewInstallWizard: React.FC<{
+  defaultDir: string;
+  onInstalled: (dir: string) => void;
+  onCancel: () => void;
+  onError: (message: string) => void;
+}> = (() => null);
+export const computeDefaultInstallDir: () => Promise<string> = (() => Promise.resolve(''));