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>

backend/modules/reports/cache/event_monitor.py

@@ -157,7 +157,7 @@ class EventMonitor:
                 # Changes detected!
                 logger.info(
                     f"Schema {schema} (company {company_id}): "
-                    f"id_act changed {cached_watermark} → {current_max}"
+                    f"id_act changed {cached_watermark} -> {current_max}"
                 )
 
                 # Update watermark