feat: production deployment configuration for dk0.dev

- Fixed authentication system (removed HTTP Basic Auth popup)
- Added session-based authentication with proper logout
- Updated rate limiting (20 req/s for login, 5 req/m for admin)
- Created production deployment scripts and configs
- Updated nginx configuration for dk0.dev domain
- Added comprehensive production deployment guide
- Fixed logout button functionality
- Optimized for production with proper resource limits

lib/auth.ts

@@ -31,8 +31,59 @@ export function requireAdminAuth(request: NextRequest): Response | null {
       { 
         status: 401, 
         headers: { 
-          'Content-Type': 'application/json',
-          'WWW-Authenticate': 'Basic realm="Admin Access"'
+          'Content-Type': 'application/json'
+        } 
+      }
+    );
+  }
+  return null;
+}
+
+// Session-based authentication (no browser popup)
+export function verifySessionAuth(request: NextRequest): boolean {
+  // Check for session token in headers
+  const sessionToken = request.headers.get('x-session-token');
+  if (!sessionToken) return false;
+
+  try {
+    // Decode and validate session token
+    const decodedJson = atob(sessionToken);
+    const sessionData = JSON.parse(decodedJson);
+
+    // Validate session data structure
+    if (!sessionData.timestamp || !sessionData.random || !sessionData.ip || !sessionData.userAgent) {
+      return false;
+    }
+
+    // Check if session is still valid (2 hours)
+    const sessionTime = sessionData.timestamp;
+    const now = Date.now();
+    const sessionDuration = 2 * 60 * 60 * 1000; // 2 hours
+
+    if (now - sessionTime > sessionDuration) {
+      return false;
+    }
+
+    // Validate IP address (optional, but good security practice)
+    const currentIp = request.headers.get('x-forwarded-for') || request.headers.get('x-real-ip') || 'unknown';
+    if (sessionData.ip !== currentIp) {
+      return false;
+    }
+
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+export function requireSessionAuth(request: NextRequest): Response | null {
+  if (!verifySessionAuth(request)) {
+    return new Response(
+      JSON.stringify({ error: 'Session expired or invalid' }), 
+      { 
+        status: 401, 
+        headers: { 
+          'Content-Type': 'application/json'
         } 
       }
     );
@@ -43,6 +94,19 @@ export function requireAdminAuth(request: NextRequest): Response | null {
 // Rate limiting for admin endpoints
 const rateLimitMap = new Map<string, { count: number; resetTime: number }>();
 
+// Clear rate limit cache on startup
+if (typeof window === 'undefined') {
+  // Server-side: clear cache periodically
+  setInterval(() => {
+    const now = Date.now();
+    for (const [key, value] of rateLimitMap.entries()) {
+      if (now > value.resetTime) {
+        rateLimitMap.delete(key);
+      }
+    }
+  }, 60000); // Clear every minute
+}
+
 export function checkRateLimit(ip: string, maxRequests: number = 10, windowMs: number = 60000): boolean {
   const now = Date.now();
   const key = `admin_${ip}`;