build: Vite 单文件构建 + 修复 doubaoime-asr 打包后 WASM 加载失败

- vite.config.ts: codeSplitting: false 替代多 chunk 输出，产出单文件 dist/cli.js
- vite.config.ts: ssr.external 排除 doubaoime-asr/opus-encdec，避免 require.resolve 路径失效
- scripts/post-build.ts: 简化为直接处理单文件 dist/cli.js
- src/services/doubaoSTT.ts: 改进错误信息，输出具体异常内容便于排查

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/post-build.ts

@@ -14,20 +14,18 @@ import { execSync } from 'node:child_process'
 const outdir = 'dist'
 
 async function postBuild() {
-  // Step 1: Patch globalThis.Bun destructuring from third-party deps
-  const files = await readdir(outdir, { recursive: true })
+  // Step 1: Patch globalThis.Bun destructuring in the single bundled file
+  const cliPath = join(outdir, 'cli.js')
   const BUN_DESTRUCTURE = /var \{([^}]+)\} = globalThis\.Bun;?/g
   const BUN_DESTRUCTURE_SAFE =
     'var {$1} = typeof globalThis.Bun !== "undefined" ? globalThis.Bun : {};'
 
   let bunPatched = 0
-  for (const file of files) {
-    const filePath = join(outdir, file)
-    if (typeof file !== 'string' || !file.endsWith('.js')) continue
-    const content = await readFile(filePath, 'utf-8')
+  {
+    const content = await readFile(cliPath, 'utf-8')
     if (BUN_DESTRUCTURE.test(content)) {
       await writeFile(
-        filePath,
+        cliPath,
         content.replace(BUN_DESTRUCTURE, BUN_DESTRUCTURE_SAFE),
       )
       bunPatched++