fix caching: network-first HTML, no-cache headers, bump SW to v3

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_headers

@@ -0,0 +1,8 @@
+/*.html
+  Cache-Control: no-cache, no-store, must-revalidate
+
+/
+  Cache-Control: no-cache, no-store, must-revalidate
+
+/service-worker.js
+  Cache-Control: no-cache, no-store, must-revalidate

service-worker.js

@@ -1,8 +1,8 @@
-const CACHE = 'noted-v2';
+const CACHE = 'noted-v3';
-const ASSETS = ['./', './index.html', './manifest.json', './fry.png'];
+const STATIC = ['./fry.png', './manifest.json'];
 
 self.addEventListener('install', e => {
-    e.waitUntil(caches.open(CACHE).then(c => c.addAll(ASSETS)));
+    e.waitUntil(caches.open(CACHE).then(c => c.addAll(STATIC)));
     self.skipWaiting();
 });
 
@@ -14,15 +14,22 @@ self.addEventListener('activate', e => {
 });
 
 self.addEventListener('fetch', e => {
+    // Skip API calls entirely
     if (e.request.url.includes('/api/')) return;
+
+    // HTML: always network-first so updates are instant
+    if (e.request.mode === 'navigate') {
+        e.respondWith(
+            fetch(e.request).catch(() => caches.match('./index.html'))
+        );
+        return;
+    }
+
+    // Static assets: cache-first
     e.respondWith(
         caches.match(e.request).then(cached => cached || fetch(e.request).then(res => {
-            if (res.ok && e.request.method === 'GET') {
+            if (res.ok) caches.open(CACHE).then(c => c.put(e.request, res.clone()));
-                caches.open(CACHE).then(c => c.put(e.request, res.clone()));
-            }
             return res;
-        }).catch(() => {
-            if (e.request.mode === 'navigate') return caches.match('./index.html');
         }))
     );
 });