fix: resolve TypeScript compilation errors in OAuth diagnostic endpoints

- Add 'any' type annotation to diagnostics objects to fix property access errors
- Fix async headers() call in Next.js 15 by adding await
- These fixes allow successful TypeScript compilation for Vercel deployment

Author: doublegate

src/app/api/auth/check-oauth-flow/route.ts

@@ -4,7 +4,7 @@ export async function GET(request: Request) {
   const { searchParams } = new URL(request.url);
   const provider = searchParams.get('provider') || 'google';
 
-  const diagnostics = {
+  const diagnostics: any = {
     timestamp: new Date().toISOString(),
     provider,
 
@@ -14,6 +14,9 @@ export async function GET(request: Request) {
       NEXTAUTH_URL: process.env.NEXTAUTH_URL,
       VERCEL_URL: process.env.VERCEL_URL,
       hasSecret: !!process.env.NEXTAUTH_SECRET,
+      envModuleLoaded: false,
+      envValues: null,
+      envError: null,
     },
 
     // Provider credentials check

src/app/api/auth/diagnose-env-validation/route.ts

@@ -1,7 +1,7 @@
 import { NextResponse } from 'next/server';
 
 export async function GET() {
-  const diagnostics = {
+  const diagnostics: any = {
     timestamp: new Date().toISOString(),
 
     // Raw process.env values

src/app/api/auth/test-oauth-flow/route.ts

@@ -4,7 +4,7 @@ import { headers } from 'next/headers';
 // Test OAuth flow and check for configuration errors
 export async function GET() {
   try {
-    const headersList = headers();
+    const headersList = await headers();
     const host = headersList.get('host') || 'localhost:3000';
     const protocol = headersList.get('x-forwarded-proto') || 'http';
     const baseUrl = `${protocol}://${host}`;