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>

supabase/migrations/20260607170000_backfill_submission_names.sql

@@ -0,0 +1,5 @@
+update public.submissions as s
+set submitted_by_name = p.name
+from public.profiles as p
+where s.submitted_by = p.id
+  and coalesce(s.submitted_by_name, '') is distinct from coalesce(p.name, '');