chore: commit previously untracked runtime files (splits, auth, participants, shared)

src/lib/auth.ts

@@ -0,0 +1,27 @@
+import { NextRequest } from "next/server";
+import { queryRaw } from "./db";
+
+export interface CurrentUser {
+  id: number;
+  name: string;
+  email: string;
+}
+
+export async function getCurrentUser(req: NextRequest): Promise<CurrentUser | null> {
+  const email = req.headers.get("x-forwarded-user");
+
+  // Dev fallback: no Traefik header → use participant id=1
+  if (!email) {
+    if (process.env.NODE_ENV === "development") {
+      const rows = await queryRaw<CurrentUser>(`SELECT id, name, email FROM participants WHERE id = 1`);
+      return rows[0] || null;
+    }
+    return null;
+  }
+
+  const rows = await queryRaw<CurrentUser>(
+    `SELECT id, name, COALESCE(email, '') as email FROM participants WHERE email = $1`,
+    [email]
+  );
+  return rows[0] || null;
+}