refactor(session): 统一导出 getExtensionRoot 函数

- 将 getExtensionRoot 函数从 session/utils.ts 移除
- 在 session/utils.ts 中重新导出 prompt.ts 中的 getExtensionRoot 函数
- 调整 prompt.ts 中 getExtensionRoot 函数的导出为 export
- 优化了 getExtensionRoot 函数的注释和环境兼容处理逻辑

Author: hqwlkj

src/prompt.ts

@@ -2,8 +2,8 @@ import { execFileSync, execSync } from "child_process";
 import * as fs from "fs";
 import * as os from "os";
 import * as path from "path";
-import { fileURLToPath } from "url";
 import ejs from "ejs";
+import { fileURLToPath } from "url";
 import type { SessionMessage } from "./session/types";
 import { findGitBashPath, resolveShellPath } from "./common/system/shell-utils";
 import { supportsMultimodal } from "./common/model-capabilities";
@@ -286,7 +286,7 @@ function getUnameInfo(): string {
   }
 }
 
-function getExtensionRoot(): string {
+export function getExtensionRoot(): string {
   // Prefer `__dirname` which is always available in the CJS bundle output.
   // Fall back to `import.meta.url` for ESM test environments (tsx --test).
   if (typeof __dirname !== "undefined") {

src/session/utils.ts

@@ -1,5 +1,3 @@
-import * as path from "path";
-import { fileURLToPath } from "url";
 import { DEEPSEEK_V4_MODELS } from "../common/model-capabilities";
 import type { ModelUsage } from "./types";
 
@@ -81,11 +79,4 @@ export function accumulateUsagePerModel(
   return usagePerModel;
 }
 
-export function getExtensionRoot(): string {
-  if (typeof __dirname !== "undefined") {
-    return path.resolve(__dirname, "../..");
-  }
-
-  const currentFilePath = fileURLToPath(import.meta.url);
-  return path.resolve(path.dirname(currentFilePath), "../..");
-}
+export { getExtensionRoot } from "../prompt";