diff --git a/next.config.ts b/next.config.ts
index 0bd2f11..9ae23a8 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -7,6 +7,9 @@ const nextConfig: NextConfig = {
     ignoreBuildErrors: true,
   },
   reactStrictMode: false,
+  allowedDevOrigins: [
+    'preview-chat-7eeacdfa-df81-4042-9a8e-7ddb7becdce4.space-z.ai',
+  ],
 };
 
 export default nextConfig;
diff --git a/public/sw.js b/public/sw.js
index fe8a2a6..ade69d1 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -1,8 +1,8 @@
 // CompetenceTrack — Service Worker for PWA Offline Support
-const CACHE_NAME = 'competencetrack-v1';
-const STATIC_CACHE = 'competencetrack-static-v1';
-const DATA_CACHE = 'competencetrack-data-v1';
-const OFFLINE_CACHE = 'competencetrack-offline-v1';
+const CACHE_NAME = 'competencetrack-v2';
+const STATIC_CACHE = 'competencetrack-static-v2';
+const DATA_CACHE = 'competencetrack-data-v2';
+const OFFLINE_CACHE = 'competencetrack-offline-v2';
 
 // Static assets to cache on install
 const STATIC_ASSETS = [
@@ -81,9 +81,16 @@ self.addEventListener('fetch', (event) => {
   }
 
   // Static assets (CSS, JS, images) — CacheFirst strategy
+  // But use NetworkFirst for JS/CSS from Next.js dev server (_next/) to avoid stale module factories
   if (
     url.pathname.endsWith('.css') ||
-    url.pathname.endsWith('.js') ||
+    url.pathname.endsWith('.js')
+  ) {
+    // Always use NetworkFirst for JS/CSS to avoid stale Turbopack chunks
+    event.respondWith(networkFirstStrategy(request, STATIC_CACHE));
+    return;
+  }
+  if (
     url.pathname.endsWith('.png') ||
     url.pathname.endsWith('.jpg') ||
     url.pathname.endsWith('.svg') ||
diff --git a/src/app/api/auth/route.ts b/src/app/api/auth/route.ts
index c52938f..4fa7708 100644
--- a/src/app/api/auth/route.ts
+++ b/src/app/api/auth/route.ts
@@ -41,7 +41,7 @@ export const POST = withRateLimit(async function POST(request: Request) {
 
       const { email, password } = parsed.data;
 
-      const user = await db.user.findUnique({
+      const user = await db.user.findFirst({
         where: { email, deletedAt: null },
       });
 
diff --git a/src/components/app-layout.tsx b/src/components/app-layout.tsx
index 3acbe3f..64094c1 100644
--- a/src/components/app-layout.tsx
+++ b/src/components/app-layout.tsx
@@ -153,6 +153,7 @@ import ResourceLibraryView from './resource-library-view';
 
 // Dynamic imports for heavy components with loading skeletons
 const AnalyticsView = dynamic(() => import('./analytics-view'), {
+  ssr: false,
   loading: () => <div className="space-y-4 p-4"><Skeleton className="h-8 w-48" /><div className="grid grid-cols-1 md:grid-cols-3 gap-4">{[1,2,3].map(i => <Skeleton key={i} className="h-32" />)}</div><Skeleton className="h-64" /></div>,
 });
 
diff --git a/src/components/dashboard-view.tsx b/src/components/dashboard-view.tsx
index 043c11a..6fee8db 100644
--- a/src/components/dashboard-view.tsx
+++ b/src/components/dashboard-view.tsx
@@ -101,6 +101,7 @@ import { useAppStore, type ViewName, type CurrentUser } from '@/lib/store';
 import { t } from '@/lib/i18n';
 import { fetchDashboard, type DashboardData, getStoredNotifications, type AppNotification, addNotification, markNotificationsRead, fetchParentLinks, type ParentStudentLinkData, fetchStudents } from '@/lib/api';
 import { apiGet, apiPost, apiPut } from '@/lib/api';
+import { sanitizeHtml } from '@/lib/utils';
 import { fetchNewsletters, createNewsletter, type NewsletterData } from '@/lib/api';
 
 const containerVariants = {
@@ -2645,7 +2646,7 @@ function DashboardNewsletterCard({ currentUser, locale }: { currentUser: Current
                   <img src={viewingNewsletter.imageUrl} alt="" className="w-full h-48 object-cover" />
                 </div>
               )}
-              <div className="prose prose-sm dark:prose-invert max-w-none" dangerouslySetInnerHTML={{ __html: viewingNewsletter.content }} />
+              <div className="prose prose-sm dark:prose-invert max-w-none" dangerouslySetInnerHTML={{ __html: sanitizeHtml(viewingNewsletter.content) }} />
               {viewingNewsletter.tags && (() => {
                 try {
                   const parsed = JSON.parse(viewingNewsletter.tags);
diff --git a/src/lib/auth.ts b/src/lib/auth.ts
index 390c12a..39935c7 100644
--- a/src/lib/auth.ts
+++ b/src/lib/auth.ts
@@ -53,7 +53,7 @@ export async function getSession(): Promise<{
 
   if (!userId) return null;
 
-  const user = await db.user.findUnique({
+  const user = await db.user.findFirst({
     where: { id: userId, deletedAt: null },
     select: sessionUserSelect,
   });
diff --git a/src/lib/rate-limit.ts b/src/lib/rate-limit.ts
index 653d350..2d44eb2 100644
--- a/src/lib/rate-limit.ts
+++ b/src/lib/rate-limit.ts
@@ -23,8 +23,8 @@ setInterval(() => {
 // ─── Preset Limits ────────────────────────────────────────────────────
 
 export const RATE_LIMITS = {
-  // Auth endpoints: 5 requests per minute (strict)
-  auth: { limit: 5, windowMs: 60 * 1000 },
+  // Auth endpoints: 20 requests per minute (allows retries & multiple tabs)
+  auth: { limit: 20, windowMs: 60 * 1000 },
 
   // Data read endpoints: 60 requests per minute (generous)
   dataRead: { limit: 60, windowMs: 60 * 1000 },
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index bd0c391..b9f8576 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -4,3 +4,24 @@ import { twMerge } from "tailwind-merge"
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
 }
+
+/**
+ * Sanitize HTML content by removing script tags and dangerous event handlers.
+ * This prevents React's "Encountered a script tag" warning and XSS attacks
+ * when using dangerouslySetInnerHTML.
+ */
+export function sanitizeHtml(html: string): string {
+  if (!html) return '';
+  return html
+    // Remove <script> tags and their content
+    .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '')
+    // Remove on* event handler attributes (onclick, onload, onerror, etc.)
+    .replace(/\s+on\w+\s*=\s*(?:"[^"]*"|'[^']*'|[^\s>]+)/gi, '')
+    // Remove javascript: URLs
+    .replace(/href\s*=\s*(?:"javascript:[^"]*"|'javascript:[^']*')/gi, 'href="#"')
+    // Remove <iframe> tags
+    .replace(/<iframe\b[^<]*(?:(?!<\/iframe>)<[^<]*)*<\/iframe>/gi, '')
+    // Remove <object> and <embed> tags
+    .replace(/<object\b[^<]*(?:(?!<\/object>)<[^<]*)*<\/object>/gi, '')
+    .replace(/<embed\b[^>]*>/gi, '');
+}