feat: Add PWA support and consolidate CSS design system

- Add PWA manifest, icons (192x192, 512x512), and service worker
- Register service worker in index.html with Apple mobile web app support
- Consolidate CSS variables and design tokens documentation
- Update PrimeVue overrides for consistent theming
- Refactor data-entry components to use shared CSS patterns
- Add frontend-style-auditor agent for style consistency checks
- Minor OCR validation and job worker improvements
- Update start-prod.sh configuration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

public/sw.js

@@ -0,0 +1,62 @@
+// Service Worker for ROA2WEB PWA
+// Network-first strategy to always show fresh content
+
+const CACHE_VERSION = 'v2';
+const CACHE_NAME = `roa2web-${CACHE_VERSION}`;
+
+// Install event - skip waiting to activate immediately
+self.addEventListener('install', (event) => {
+  console.log('[SW] Installing service worker...');
+  self.skipWaiting();
+});
+
+// Activate event - clear old caches and claim clients
+self.addEventListener('activate', (event) => {
+  console.log('[SW] Service worker activated');
+  event.waitUntil(
+    Promise.all([
+      // Clear all old caches
+      caches.keys().then(cacheNames => {
+        return Promise.all(
+          cacheNames.map(cacheName => {
+            if (cacheName !== CACHE_NAME) {
+              console.log('[SW] Deleting old cache:', cacheName);
+              return caches.delete(cacheName);
+            }
+          })
+        );
+      }),
+      // Take control of all clients immediately
+      clients.claim()
+    ])
+  );
+});
+
+// Fetch event - ALWAYS network first, no caching for HTML/JS/CSS
+self.addEventListener('fetch', (event) => {
+  const url = new URL(event.request.url);
+
+  // Skip non-GET requests
+  if (event.request.method !== 'GET') {
+    return;
+  }
+
+  // API calls - always network, no cache
+  if (url.pathname.includes('/api/')) {
+    event.respondWith(fetch(event.request));
+    return;
+  }
+
+  // HTML, JS, CSS - always fetch fresh from network
+  // This ensures PWA always loads latest version
+  event.respondWith(
+    fetch(event.request)
+      .then(response => {
+        return response;
+      })
+      .catch(() => {
+        // Only fallback to cache if network fails
+        return caches.match(event.request);
+      })
+  );
+});