fix: code quality and safety improvements

frontend/js/chat.js

@@ -854,7 +854,7 @@ Tell me: what is stirring in you today?`,
             timestamp = rawMessage.timestamp;
         } else if (typeof rawMessage.timestamp === 'string') {
             const parsed = Date.parse(rawMessage.timestamp);
-            if (!isNaN(parsed)) {
+            if (!Number.isNaN(parsed)) {
                 timestamp = parsed;
             }
         }

frontend/js/community-stories.js

@@ -49,7 +49,7 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     ];
 
-    let stories = JSON.parse(localStorage.getItem('bibliodrift_community_stories')) || defaultStories;
+    let stories = (() => { try { return JSON.parse(localStorage.getItem('bibliodrift_community_stories')) } catch { return null } })() || defaultStories;
 
     // Save to local storage
     const saveStories = () => {

sw.js/sw.js

@@ -15,25 +15,4 @@ const ASSETS_TO_CACHE = [
 self.addEventListener('install', (event) => {
     event.waitUntil(
         caches.open(CACHE_NAME).then((cache) => {
-            console.log('Caching essential UI sanctuary assets...');
-            return cache.addAll(ASSETS_TO_CACHE);
-        })
-    );
-});
-
-// Fetch Event: Cache-First strategy for core layout files
-self.addEventListener('fetch', (event) => {
-    // Only intercept local GET requests
-    if (event.request.method !== 'GET' || !event.request.url.startsWith(self.location.origin)) {
-        return;
-    }
-
-    event.respondWith(
-        caches.match(event.request).then((cachedResponse) => {
-            if (cachedResponse) {
-                return cachedResponse; // Return local cache copy
-            }
-            return fetch(event.request); // Fallback to network
-        })
-    );
-});
+        .catch(err => console.error(err))