Remove Apple SSO, keep Google + GitHub only

- Removed Apple from OAuth lib (config, exchange, provider type)
- Removed Apple button from auth page
- Removed Apple tab from setup guide page
- Removed Apple env vars from .env, .env.example, docker-compose.yml
- Removed Apple prompts from setup-sso.sh

src/app/api/auth/[provider]/callback/route.ts

@@ -8,19 +8,19 @@ import {
 } from "@/lib/oauth";
 import { signJWT } from "@/lib/auth";
 
-const VALID_PROVIDERS = ["google", "apple", "github"];
+const VALID_PROVIDERS = ["google", "github"];
 
 async function handleCallback(
   req: NextRequest,
   provider: string
 ): Promise<NextResponse> {
   try {
-    // Grab code and state from query params or POST body (Apple uses form_post)
+    // Grab code and state from query params or POST body
     const url = new URL(req.url);
     let code = url.searchParams.get("code");
     let stateParam = url.searchParams.get("state");
 
-    // Apple may POST form data — try reading POST body
+    // Try reading POST body if code wasn't in query params
     if (!code) {
       try {
         const contentType = req.headers.get("content-type") || "";
@@ -138,20 +138,3 @@ export async function GET(
   }
   return handleCallback(req, provider);
 }
-
-/** Apple OAuth may use form_post response_mode, which sends a POST. */
-export async function POST(
-  req: NextRequest,
-  { params }: { params: Promise<{ provider: string }> }
-) {
-  const { provider } = await params;
-  if (!VALID_PROVIDERS.includes(provider)) {
-    return NextResponse.json(
-      {
-        error: `Unsupported provider. Must be one of: ${VALID_PROVIDERS.join(", ")}`,
-      },
-      { status: 400 }
-    );
-  }
-  return handleCallback(req, provider);
-}