feat: Add installable Android PWA and native Android Web Share Target support

public/sw.js

@@ -0,0 +1,74 @@
+// Everclone PWA Service Worker (v1.0.0)
+const CACHE_NAME = 'everclone-cache-v1';
+const PRECACHE_URLS = [
+  '/',
+  '/manifest.json',
+  '/icon.svg',
+  '/icon-192.png',
+  '/icon-512.png',
+  '/apple-touch-icon.png'
+];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => {
+      return cache.addAll(PRECACHE_URLS).catch(() => {});
+    })
+  );
+  self.skipWaiting();
+});
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches.keys().then((keys) => {
+      return Promise.all(
+        keys.filter((key) => key !== CACHE_NAME).map((key) => caches.delete(key))
+      );
+    })
+  );
+  self.clients.claim();
+});
+
+self.addEventListener('fetch', (event) => {
+  // CRITICAL: Never intercept POST/PUT/DELETE requests!
+  // This ensures Android Web Share Target multipart POSTs stream directly to /api/hooks/note
+  if (event.request.method !== 'GET') {
+    return;
+  }
+
+  const url = new URL(event.request.url);
+
+  // Bypass API endpoints and file downloads to always get fresh data
+  if (url.pathname.startsWith('/api/')) {
+    return;
+  }
+
+  // Network-first strategy for navigation and static assets with cache fallback
+  event.respondWith(
+    fetch(event.request)
+      .then((networkResponse) => {
+        if (
+          networkResponse &&
+          networkResponse.status === 200 &&
+          (url.pathname === '/' || url.pathname.startsWith('/_next/static/'))
+        ) {
+          const responseClone = networkResponse.clone();
+          caches.open(CACHE_NAME).then((cache) => {
+            cache.put(event.request, responseClone);
+          });
+        }
+        return networkResponse;
+      })
+      .catch(() => {
+        return caches.match(event.request).then((cachedResponse) => {
+          if (cachedResponse) {
+            return cachedResponse;
+          }
+          if (event.request.mode === 'navigate') {
+            return caches.match('/');
+          }
+          return new Response('Network error occurred', { status: 503, statusText: 'Offline' });
+        });
+      })
+  );
+});