feat(auth): add admin authentication with HMAC session cookies

- Create admin-session lib with sign/verify helpers using HMAC-SHA256
- Add admin login API that checks hardcoded super/admin credentials
  and DB-stored admin users with bcrypt password comparison
- Add admin logout API to clear session cookie
- Add change-password API for admin self-service password changes
- Create admin login page with Macedonian UI
- Update middleware to protect /admin/* and /api/admin/* routes
  with admin session check, bypassing Clerk auth

src/app/admin/login/page.tsx

@@ -0,0 +1,78 @@
+"use client";
+
+import { useState } from "react";
+import { useRouter } from "next/navigation";
+
+export default function AdminLoginPage() {
+  const router = useRouter();
+  const [username, setUsername] = useState("");
+  const [password, setPassword] = useState("");
+  const [error, setError] = useState("");
+  const [loading, setLoading] = useState(false);
+
+  const handleSubmit = async (e: React.FormEvent) => {
+    e.preventDefault();
+    setLoading(true);
+    setError("");
+    try {
+      const res = await fetch("/api/admin/login", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ username, password }),
+      });
+      const data = await res.json();
+      if (!res.ok) {
+        throw new Error(data.error || "Најавата не успеа");
+      }
+      router.push("/admin/dashboard");
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Најавата не успеа");
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <div className="flex min-h-screen items-center justify-center bg-stone-100">
+      <div className="w-full max-w-sm rounded-lg bg-white p-8 shadow-sm">
+        <h1 className="mb-6 text-center text-xl font-semibold text-stone-900">Администрација</h1>
+        <form onSubmit={handleSubmit} className="space-y-4">
+          <div>
+            <label htmlFor="username" className="block text-sm font-medium text-stone-700">
+              Корисничко име
+            </label>
+            <input
+              id="username"
+              type="text"
+              value={username}
+              onChange={(e) => setUsername(e.target.value)}
+              className="mt-1 block w-full rounded-lg border border-stone-200 px-3 py-2.5 text-stone-900 placeholder:text-stone-400 focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary"
+              autoComplete="username"
+            />
+          </div>
+          <div>
+            <label htmlFor="password" className="block text-sm font-medium text-stone-700">
+              Лозинка
+            </label>
+            <input
+              id="password"
+              type="password"
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              className="mt-1 block w-full rounded-lg border border-stone-200 px-3 py-2.5 text-stone-900 placeholder:text-stone-400 focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary"
+              autoComplete="current-password"
+            />
+          </div>
+          {error && <p className="text-sm text-red-600">{error}</p>}
+          <button
+            type="submit"
+            disabled={loading || !username || !password}
+            className="w-full rounded-lg bg-primary px-6 py-2.5 text-sm font-medium text-white transition-colors hover:bg-primary-light disabled:cursor-not-allowed disabled:opacity-50"
+          >
+            {loading ? "Најавување..." : "Најави се"}
+          </button>
+        </form>
+      </div>
+    </div>
+  );
+}

src/app/api/admin/change-password/route.ts

@@ -0,0 +1,45 @@
+import { NextRequest, NextResponse } from "next/server";
+import { hash, compare } from "bcryptjs";
+import { prisma } from "@/lib/prisma";
+import { getAdminSession } from "@/lib/admin-session";
+
+export async function POST(req: NextRequest) {
+  try {
+    const session = await getAdminSession();
+    if (!session) {
+      return NextResponse.json({ error: "Неавторизирано" }, { status: 401 });
+    }
+    if (session.username === "super") {
+      return NextResponse.json({ error: "SuperAdmin не може да ја промени лозинката преку овој метод" }, { status: 400 });
+    }
+
+    const { currentPassword, newPassword } = await req.json();
+    if (!currentPassword || !newPassword) {
+      return NextResponse.json({ error: "Тековната и новата лозинка се задолжителни" }, { status: 400 });
+    }
+    if (newPassword.length < 6) {
+      return NextResponse.json({ error: "Новата лозинка мора да има најмалку 6 карактери" }, { status: 400 });
+    }
+
+    const admin = await prisma.adminUser.findUnique({ where: { username: session.username } });
+    if (!admin) {
+      return NextResponse.json({ error: "Администраторот не е пронајден" }, { status: 404 });
+    }
+
+    const valid = await compare(currentPassword, admin.passwordHash);
+    if (!valid) {
+      return NextResponse.json({ error: "Тековната лозинка е неточна" }, { status: 401 });
+    }
+
+    const passwordHash = await hash(newPassword, 12);
+    await prisma.adminUser.update({
+      where: { username: session.username },
+      data: { passwordHash },
+    });
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error("Change password error:", error);
+    return NextResponse.json({ error: "Внатрешна грешка на серверот" }, { status: 500 });
+  }
+}

src/app/api/admin/login/route.ts

@@ -0,0 +1,41 @@
+import { NextRequest, NextResponse } from "next/server";
+import { compare } from "bcryptjs";
+import { prisma } from "@/lib/prisma";
+import { createAdminSession, cookieOptions } from "@/lib/admin-session";
+
+const SUPER_USERNAME = "super";
+const SUPER_PASSWORD = "admin";
+
+export async function POST(req: NextRequest) {
+  try {
+    const { username, password } = await req.json();
+    if (!username || !password) {
+      return NextResponse.json({ error: "Корисничко име и лозинка се задолжителни" }, { status: 400 });
+    }
+
+    if (username === SUPER_USERNAME && password === SUPER_PASSWORD) {
+      const session = createAdminSession({ username: SUPER_USERNAME, role: "SUPER_ADMIN" });
+      const res = NextResponse.json({ success: true });
+      res.cookies.set(cookieOptions(session));
+      return res;
+    }
+
+    const admin = await prisma.adminUser.findUnique({ where: { username } });
+    if (!admin) {
+      return NextResponse.json({ error: "Невалидно корисничко име или лозинка" }, { status: 401 });
+    }
+
+    const valid = await compare(password, admin.passwordHash);
+    if (!valid) {
+      return NextResponse.json({ error: "Невалидно корисничко име или лозинка" }, { status: 401 });
+    }
+
+    const session = createAdminSession({ username: admin.username, role: admin.role });
+    const res = NextResponse.json({ success: true });
+    res.cookies.set(cookieOptions(session));
+    return res;
+  } catch (error) {
+    console.error("Admin login error:", error);
+    return NextResponse.json({ error: "Внатрешна грешка на серверот" }, { status: 500 });
+  }
+}

src/app/api/admin/logout/route.ts

@@ -0,0 +1,15 @@
+import { NextResponse } from "next/server";
+
+export async function POST() {
+  const res = NextResponse.json({ success: true });
+  res.cookies.set({
+    name: "admin_session",
+    value: "",
+    httpOnly: true,
+    secure: process.env.NODE_ENV === "production",
+    sameSite: "lax",
+    path: "/admin",
+    maxAge: 0,
+  });
+  return res;
+}

src/lib/admin-session.ts

@@ -0,0 +1,68 @@
+import { cookies } from "next/headers";
+import { createHmac, timingSafeEqual } from "crypto";
+
+const COOKIE_NAME = "admin_session";
+const SEP = ".";
+
+function getSecret(): string {
+  const secret = process.env.ADMIN_SESSION_SECRET;
+  if (!secret) throw new Error("ADMIN_SESSION_SECRET env var is not set");
+  return secret;
+}
+
+function sign(payload: string): string {
+  const hmac = createHmac("sha256", getSecret());
+  hmac.update(payload);
+  return hmac.digest("base64url");
+}
+
+export interface AdminSession {
+  username: string;
+  role: "SUPER_ADMIN" | "ADMIN";
+}
+
+export function createAdminSession(data: AdminSession): string {
+  const payload = Buffer.from(JSON.stringify(data)).toString("base64url");
+  return payload + SEP + sign(payload);
+}
+
+export function verifyAdminSession(token: string): AdminSession | null {
+  const sepIdx = token.lastIndexOf(SEP);
+  if (sepIdx === -1) return null;
+  const payload = token.slice(0, sepIdx);
+  const sig = token.slice(sepIdx + 1);
+  const expectedSig = sign(payload);
+  const sigBuf = Buffer.from(sig);
+  const expectedBuf = Buffer.from(expectedSig);
+  if (sigBuf.length !== expectedBuf.length) return null;
+  try {
+    if (!timingSafeEqual(sigBuf, expectedBuf)) return null;
+  } catch {
+    return null;
+  }
+  try {
+    return JSON.parse(Buffer.from(payload, "base64url").toString("utf-8"));
+  } catch {
+    return null;
+  }
+}
+
+export async function getAdminSession(): Promise<AdminSession | null> {
+  const store = await cookies();
+  const token = store.get(COOKIE_NAME)?.value;
+  if (!token) return null;
+  return verifyAdminSession(token);
+}
+
+export const COOKIE_NAME_ADMIN = COOKIE_NAME;
+
+export function cookieOptions(value: string) {
+  return {
+    name: COOKIE_NAME,
+    value,
+    httpOnly: true,
+    secure: process.env.NODE_ENV === "production",
+    sameSite: "lax" as const,
+    path: "/admin",
+  };
+}

src/middleware.ts

@@ -1,9 +1,14 @@
 import { clerkMiddleware, createRouteMatcher } from "@clerk/nextjs/server";
 import { NextResponse } from "next/server";
 import type { NextRequest } from "next/server";
+import { verifyAdminSession, COOKIE_NAME_ADMIN } from "@/lib/admin-session";
 
 const isProtectedRoute = createRouteMatcher(["/dashboard(.*)", "/onboarding(.*)", "/api/publish(.*)", "/api/upload(.*)", "/api/user(.*)"]);
 
+function isAdminRoute(pathname: string): boolean {
+  return pathname.startsWith("/admin") || pathname.startsWith("/api/admin");
+}
+
 function getSubdomain(req: NextRequest): string | null {
   const host = req.headers.get("host");
   if (!host) return null;
@@ -25,6 +30,22 @@ function getSubdomain(req: NextRequest): string | null {
 }
 
 export default clerkMiddleware(async (auth, req: NextRequest) => {
+  if (isAdminRoute(req.nextUrl.pathname)) {
+    if (req.nextUrl.pathname === "/admin/login") {
+      return NextResponse.next();
+    }
+
+    const token = req.cookies.get(COOKIE_NAME_ADMIN)?.value;
+    if (!token || !verifyAdminSession(token)) {
+      if (req.nextUrl.pathname.startsWith("/api/")) {
+        return NextResponse.json({ error: "Неавторизирано" }, { status: 401 });
+      }
+      return NextResponse.redirect(new URL("/admin/login", req.url));
+    }
+
+    return NextResponse.next();
+  }
+
   if (isProtectedRoute(req)) {
     await auth.protect();
   }