Fix Twitch OAuth redirect URI and update setup instructions

php/auth/twitch/login.php

@@ -0,0 +1,19 @@
+<?php
+// php/auth/twitch/login.php - Initiates Twitch OAuth flow
+
+require_once '../../config.php';
+
+// Scopes required to get user's email and channel info
+$scopes = "user:read:email chat:read"; // Ensure chat:read is included
+
+$auth_url = (
+    "https://id.twitch.tv/oauth2/authorize" .
+    "?client_id=" . TWITCH_CLIENT_ID .
+    "&redirect_uri=" . TWITCH_REDIRECT_URI .
+    "&response_type=code" .
+    "&scope=" . urlencode($scopes)
+);
+
+header("Location: " . $auth_url);
+exit();
+?>