Add ChronoSeal product website

www/sw.js

@@ -0,0 +1,99 @@
+/* ============================================================
+   ChronoSeal Website — Service Worker (sw.js)
+   Enables PWA offline capabilities and asset caching
+   ============================================================ */
+
+var CACHE_NAME = 'chronoseal-cache-v1';
+var ASSETS = [
+  '/',
+  '/index.html',
+  '/architecture.html',
+  '/protocol.html',
+  '/api.html',
+  '/deployment.html',
+  '/threat-model.html',
+  '/performance.html',
+  '/philosophy.html',
+  '/privacy.html',
+  '/security.html',
+  '/operations.html',
+  '/testing.html',
+  '/comparison.html',
+  '/css/chronoseal.css',
+  '/css/docs.css',
+  '/css/print.css',
+  '/js/app.js',
+  '/js/search.js',
+  '/js/diagrams.js',
+  '/js/pwa.js',
+  '/assets/logo.svg',
+  '/assets/logo.png',
+  '/site.webmanifest',
+  '/robots.txt'
+];
+
+/* Install Event — Pre-cache critical assets */
+self.addEventListener('install', function (e) {
+  e.waitUntil(
+    caches.open(CACHE_NAME).then(function (cache) {
+      return cache.addAll(ASSETS);
+    }).then(function () {
+      return self.skipWaiting();
+    })
+  );
+});
+
+/* Activate Event — Clean up old caches */
+self.addEventListener('activate', function (e) {
+  e.waitUntil(
+    caches.keys().then(function (keys) {
+      return Promise.all(
+        keys.map(function (key) {
+          if (key !== CACHE_NAME) {
+            return caches.delete(key);
+          }
+        })
+      );
+    }).then(function () {
+      return self.clients.claim();
+    })
+  );
+});
+
+/* Fetch Event — Cache-first with Network Fallback */
+self.addEventListener('fetch', function (e) {
+  // Only handle GET requests and local requests
+  if (e.request.method !== 'GET') return;
+  
+  var url = new URL(e.request.url);
+  if (url.origin !== self.location.origin) return;
+
+  e.respondWith(
+    caches.match(e.request).then(function (cachedResponse) {
+      if (cachedResponse) {
+        // Fetch fresh in background to update cache (stale-while-revalidate)
+        fetch(e.request).then(function (networkResponse) {
+          if (networkResponse.status === 200) {
+            caches.open(CACHE_NAME).then(function (cache) {
+              cache.put(e.request, networkResponse);
+            });
+          }
+        }).catch(function() {
+          /* Ignore background fetch errors (e.g. offline) */
+        });
+        return cachedResponse;
+      }
+
+      return fetch(e.request).then(function (networkResponse) {
+        if (!networkResponse || networkResponse.status !== 200 || networkResponse.type !== 'basic') {
+          return networkResponse;
+        }
+        var responseToCache = networkResponse.clone();
+        caches.open(CACHE_NAME).then(function (cache) {
+          cache.put(e.request, responseToCache);
+        });
+        return networkResponse;
+      });
+    })
+  );
+});