Refactor transcript fetching (#5)

* refactor: share transcript fetch helper

* Update lib/fetchTranscript.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update lib/fetchTranscript.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

pages/api/admin/refresh-sessions.ts

@@ -2,6 +2,7 @@
 import { NextApiRequest, NextApiResponse } from "next";
 import { fetchAndParseCsv } from "../../../lib/csvFetcher";
 import { prisma } from "../../../lib/prisma";
+import { fetchTranscriptContent } from "../../../lib/fetchTranscript";
 
 interface SessionCreateData {
   id: string;
@@ -11,41 +12,6 @@ interface SessionCreateData {
   [key: string]: unknown;
 }
 
-/**
- * Fetches transcript content from a URL with optional authentication
- * @param url The URL to fetch the transcript from
- * @param username Optional username for Basic Auth
- * @param password Optional password for Basic Auth
- * @returns The transcript content or null if fetching fails
- */
-async function fetchTranscriptContent(
-  url: string,
-  username?: string,
-  password?: string
-): Promise<string | null> {
-  try {
-    const authHeader =
-      username && password
-        ? "Basic " + Buffer.from(`${username}:${password}`).toString("base64")
-        : undefined;
-
-    const response = await fetch(url, {
-      headers: authHeader ? { Authorization: authHeader } : {},
-    });
-
-    if (!response.ok) {
-      process.stderr.write(
-        `Error fetching transcript: ${response.statusText}\n`
-      );
-      return null;
-    }
-    return await response.text();
-  } catch (error) {
-    process.stderr.write(`Failed to fetch transcript: ${error}\n`);
-    return null;
-  }
-}
-
 export default async function handler(
   req: NextApiRequest,
   res: NextApiResponse