feat(uat-b1): ship Wave A-E of Bucket 1 audit findings

Wave A (Interest+EOI form quick wins):
- Auto-select yacht after inline-create from interest form
- EOI generate dialog: "View EOI" action toast
- Interest form berth picker: formatBerthRange compact label
- Remove "Generate EOI" button from Documents tab (clean removal)
- Interest auto-assign: only sales_agent/sales_manager auto-claim
  ownership on create (explicit role check via user_port_roles join)
- LinkedBerthRowItem dims: drop "D" suffix + "L × W" format
- ExternalEoiUploadDialog: prefillSignatories prop threaded from
  active EOI signers
- EOI signature progress on Overview milestone card footer

Wave B (a11y + i18n sweeps):
- aria-live on supplemental-info error state
- text-[10px] -> text-xs in client-pipeline-summary
- Currency formatter: locale default removed (Intl uses runtime)
- en-US/en-GB hardcoded toLocaleString swept across 13 components

Wave C (Primary berth always in EOI bundle):
- Service guard strengthened on update path
- Migration 0083 backfills historical primary rows

Wave D (Onboarding super_admin discoverability):
- /api/v1/admin/onboarding/status endpoint + shared service
- Topbar OnboardingBanner (super_admin, session-dismissible)
- OnboardingTile dashboard widget (rail group, self-hides at 100%)
- Celebration toast + invalidate of shared status on last tick

Wave E (Branded post-completion email idempotency):
- Verified handleDocumentCompleted already owns the email fan-out
- Added regression test for the polling path + idempotency

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/dashboard/date-range-picker.tsx

@@ -32,7 +32,7 @@ function formatCustom(range: { from: string; to: string }): string {
   const fmt: Intl.DateTimeFormatOptions = sameYear
     ? { month: 'short', day: 'numeric', timeZone: 'UTC' }
     : { month: 'short', day: 'numeric', year: 'numeric', timeZone: 'UTC' };
-  return `${from.toLocaleDateString('en-US', fmt)} – ${to.toLocaleDateString('en-US', fmt)}`;
+  return `${from.toLocaleDateString(undefined, fmt)} – ${to.toLocaleDateString(undefined, fmt)}`;
 }
 
 /**