fix: crash bugs in TeamInvoices + faster load

Bug fixes:
- TeamInvoices: add useAuth import/currentUser (invoice-create crash)
- TeamInvoices: setChartYear -> setExportYear (year-dropdown crash)
- TeamDashboard: drop redundant setState-in-effect (cascading renders)
- Companies: delete dead _UnusedClientCompanies (illegal hook calls)
- annotate intentional empty PDF-fallback catches

Load speed:
- preconnect/dns-prefetch to Supabase origin
- lazy-load heic-to in Converters: page chunk 2737KB -> 9KB
- split recharts into its own 'charts' vendor chunk

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vite.config.js

@@ -10,6 +10,7 @@ export default defineConfig({
       output: {
         manualChunks(id) {
           if (id.includes('node_modules/jspdf')) return 'pdf-libs';
+          if (id.includes('node_modules/recharts') || id.includes('node_modules/d3-') || id.includes('node_modules/victory-vendor')) return 'charts';
           if (id.includes('node_modules/react') || id.includes('node_modules/react-dom') || id.includes('node_modules/react-router')) return 'react-vendor';
         },
       },