perf: Vite 构建启用 code splitting，Bun RSS 从 966MB 降至 35MB

Bun/JSC 全量解析单文件大 JS 的 bytecode 和 JIT，17MB 产物导致
RSS 暴涨至 ~1GB（Node/V8 懒解析仅需 ~220MB）。启用代码分割后
Bun 按需加载 chunk，--version RSS 35MB，完整加载 ~500MB。

改动：
- vite.config.ts: 移除 codeSplitting:false，添加 chunkFileNames
- post-build.ts: 遍历 dist/ + dist/chunks/ 所有文件做 Bun patch
- 新建 distRoot.ts 共享工具函数，统一路径定位逻辑
- ripgrep.ts/computerUse/setup.ts/claudeInChrome/setup.ts/updateCCB.ts:
  用 distRoot 替换内联 import.meta.url 路径推算

src/cli/updateCCB.ts

@@ -9,9 +9,9 @@ import chalk from 'chalk'
 import { execSync } from 'node:child_process'
 import { existsSync, readFileSync } from 'node:fs'
 import { homedir } from 'node:os'
-import { join, dirname } from 'node:path'
-import { fileURLToPath } from 'node:url'
+import { join } from 'node:path'
 import { logForDebugging } from '../utils/debug.js'
+import { distRoot } from '../utils/distRoot.js'
 import { execFileNoThrowWithCwd } from '../utils/execFileNoThrow.js'
 import { gracefulShutdown } from '../utils/gracefulShutdown.js'
 import { writeToStdout } from '../utils/process.js'
@@ -19,12 +19,9 @@ import { writeToStdout } from '../utils/process.js'
 const PACKAGE_NAME = 'claude-code-best'
 
 function getCurrentVersion(): string {
-  // Read version from the nearest package.json (walks up from this file)
+  // Read version from the nearest package.json (walks up from dist root)
   try {
-    const __dirname = dirname(fileURLToPath(import.meta.url))
-    // In dev: src/cli/updateCCB.ts → ../../package.json
-    // In build: dist/chunks/xxx.js → ../../package.json (may not exist)
-    const pkgPath = join(__dirname, '..', '..', 'package.json')
+    const pkgPath = join(distRoot, '..', 'package.json')
     if (existsSync(pkgPath)) {
       const pkg = JSON.parse(readFileSync(pkgPath, 'utf-8'))
       if (pkg.version) return pkg.version

src/utils/claudeInChrome/setup.ts

@@ -2,7 +2,6 @@ import { BROWSER_TOOLS } from '@ant/claude-for-chrome-mcp'
 import { chmod, mkdir, readFile, writeFile } from 'fs/promises'
 import { homedir } from 'os'
 import { join } from 'path'
-import { fileURLToPath } from 'url'
 import {
   getIsInteractive,
   getIsNonInteractiveSession,
@@ -11,6 +10,7 @@ import {
 import { getFeatureValue_CACHED_MAY_BE_STALE } from '../../services/analytics/growthbook.js'
 import type { ScopedMcpServerConfig } from '../../services/mcp/types.js'
 import { isInBundledMode } from '../bundledMode.js'
+import { distRoot } from '../distRoot.js'
 import { getGlobalConfig, saveGlobalConfig } from '../config.js'
 import { logForDebugging } from '../debug.js'
 import {
@@ -135,9 +135,7 @@ export function setupClaudeInChrome(): {
       systemPrompt: getChromeSystemPrompt(),
     }
   } else {
-    const __filename = fileURLToPath(import.meta.url)
-    const __dirname = join(__filename, '..')
-    const cliPath = join(__dirname, 'cli.js')
+    const cliPath = join(distRoot, 'cli.js')
 
     void createWrapperScript(
       `"${process.execPath}" "${cliPath}" --chrome-native-host`,

src/utils/computerUse/setup.ts

@@ -1,10 +1,10 @@
 import { buildComputerUseTools } from '@ant/computer-use-mcp'
 import { join } from 'path'
-import { fileURLToPath } from 'url'
 import { buildMcpToolName } from '../../services/mcp/mcpStringUtils.js'
 import type { ScopedMcpServerConfig } from '../../services/mcp/types.js'
 
 import { isInBundledMode } from '../bundledMode.js'
+import { distRoot } from '../distRoot.js'
 import { CLI_CU_CAPABILITIES, COMPUTER_USE_MCP_SERVER_NAME } from './common.js'
 import { getChicagoCoordinateMode } from './gates.js'
 
@@ -34,10 +34,7 @@ export function setupComputerUseMCP(): {
   // type 'stdio' to hit the right branch. Mirrors Chrome's setup.
   const args = isInBundledMode()
     ? ['--computer-use-mcp']
-    : [
-        join(fileURLToPath(import.meta.url), '..', 'cli.js'),
-        '--computer-use-mcp',
-      ]
+    : [join(distRoot, 'cli.js'), '--computer-use-mcp']
 
   return {
     mcpConfig: {

src/utils/distRoot.ts

@@ -0,0 +1,29 @@
+import { fileURLToPath } from 'url'
+import * as path from 'path'
+
+/**
+ * Resolve the dist root directory from the current module's location.
+ *
+ * Works across all build layouts:
+ * - Single-file: dist/cli.js → dist/
+ * - Code-split:  dist/chunks/chunk-xxx.js → dist/
+ * - Dev mode:    src/utils/distRoot.ts → <project_root>/
+ */
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+
+const distRoot = (() => {
+  const parts = __dirname.split(path.sep)
+  const distIdx = parts.lastIndexOf('dist')
+  if (distIdx !== -1) {
+    return parts.slice(0, distIdx + 1).join(path.sep)
+  }
+  // Dev mode: from src/utils/ → project root
+  const srcIdx = parts.lastIndexOf('src')
+  if (srcIdx !== -1) {
+    return parts.slice(0, srcIdx).join(path.sep)
+  }
+  return __dirname
+})()
+
+export { distRoot }

src/utils/ripgrep.ts

@@ -4,9 +4,9 @@ import memoize from 'lodash-es/memoize.js'
 import { homedir } from 'os'
 import * as path from 'path'
 import { logEvent } from 'src/services/analytics/index.js'
-import { fileURLToPath } from 'url'
 import { isInBundledMode } from './bundledMode.js'
 import { logForDebugging } from './debug.js'
+import { distRoot } from './distRoot.js'
 import { isEnvDefinedFalsy } from './envUtils.js'
 import { execFileNoThrow } from './execFileNoThrow.js'
 import { findExecutable } from './findExecutable.js'
@@ -14,25 +14,9 @@ import { logError } from './log.js'
 import { getPlatform } from './platform.js'
 import { countCharInString } from './stringUtils.js'
 
-const __filename = fileURLToPath(import.meta.url)
-// we use node:path.join instead of node:url.resolve because the former doesn't encode spaces
-// In dev mode: __filename = <root>/src/utils/ripgrep.ts → __dirname = <root>/src/utils/
-// In built mode (bun): __filename = <root>/dist/chunk-xxx.js → need <root>/dist/
-// In built mode (vite): __filename = <root>/dist/chunks/chunk-xxx.js → need <root>/dist/
-// Both built modes: the dist root is at <root>/dist/ where dist/vendor/ripgrep/ lives.
 const __dirname = (() => {
-  const dir = path.dirname(__filename)
-  // Test mode: from src/utils/ → project root
-  if (process.env.NODE_ENV === 'test') return path.resolve(dir, '../../../')
-  // Check if we're inside a dist directory at any depth
-  // (dist/ or dist/chunks/) — vendor lives at <dist-root>/vendor/ripgrep/
-  const parts = dir.split(path.sep)
-  const distIdx = parts.lastIndexOf('dist')
-  if (distIdx !== -1) {
-    return parts.slice(0, distIdx + 1).join(path.sep)
-  }
-  // Dev mode: from src/utils/ → src/utils/
-  return dir
+  if (process.env.NODE_ENV === 'test') return path.resolve(distRoot)
+  return distRoot
 })()
 
 type RipgrepConfig = {