Add accounts expansion, analytics, exchange rates, API tokens, PWA support, and UI overhaul

- Expand Account model with account_type (pension, savings, liability, crypto), new banks/currencies (BTC, XMR, FCL, ROP, VOL, MEMP, MPAT, MORTGAGE), and next_payment field
- Add exchange rate endpoint (BCCR integration), analytics endpoint, paste-import for transactions, and API token management
- Add PWA manifest, service worker, and app icons
- Redesign dashboard, transactions, transfers, and login pages with theme support
- Add billing cycle selector, confirm dialog, and paste import modal components
- One-time DB reset in deploy workflow for schema migration

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/public/sw.js

@@ -0,0 +1,52 @@
+const CACHE_NAME = 'wealthysmart-v1';
+const STATIC_ASSETS = ['/', '/index.html'];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => cache.addAll(STATIC_ASSETS))
+  );
+  self.skipWaiting();
+});
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches.keys().then((keys) =>
+      Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)))
+    )
+  );
+  self.clients.claim();
+});
+
+self.addEventListener('fetch', (event) => {
+  const { request } = event;
+  const url = new URL(request.url);
+
+  // Network-first for API calls
+  if (url.pathname.startsWith('/api/')) {
+    event.respondWith(fetch(request).catch(() => caches.match(request)));
+    return;
+  }
+
+  // Cache-first for static assets
+  if (url.pathname.startsWith('/assets/')) {
+    event.respondWith(
+      caches.match(request).then((cached) => cached || fetch(request).then((res) => {
+        const clone = res.clone();
+        caches.open(CACHE_NAME).then((cache) => cache.put(request, clone));
+        return res;
+      }))
+    );
+    return;
+  }
+
+  // Network-first for navigation, fallback to cached index.html
+  if (request.mode === 'navigate') {
+    event.respondWith(
+      fetch(request).catch(() => caches.match('/index.html'))
+    );
+    return;
+  }
+
+  // Default: network with cache fallback
+  event.respondWith(fetch(request).catch(() => caches.match(request)));
+});