fix(audit-wave-10): aria-hidden sweep on decorative Lucide icons (#69)

Mechanical codemod added \`aria-hidden\` to 444 self-closing single-line
Lucide icon JSX elements across 267 .tsx files in:

- shared/, layout/, dashboard/
- admin/ (all sections)
- clients/, berths/, yachts/, companies/, interests/, documents/
- reminders/, reservations/, residential/, expenses/, email/

The regex targeted only the safe pattern \`<IconName className="..." />\`
(no other props, self-closing, capitalized component name). Every match
inspected is a decorative companion to visible text or sits inside a
button whose accessible name comes from \`aria-label\` / sr-only text
— the icon itself should not be announced.

Screen readers no longer double-read the icon + the adjacent label
text (e.g. "Pencil Pencil Edit" → just "Edit"). The existing
@axe-core/playwright smoke test (\`20-accessibility.spec.ts\`) continues
to pass.

Test suite stays at 1315/1315 vitest. typescript clean.

Closes task #69 (aria-hidden sweep) from the AUDIT-2026-05-12 follow-ups
backlog.

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

src/components/admin/onboarding-checklist.tsx

@@ -228,11 +228,11 @@ export function OnboardingChecklist() {
                     }
                   >
                     {done ? (
-                      <Check className="h-4 w-4" />
+                      <Check className="h-4 w-4" aria-hidden />
                     ) : loading ? (
-                      <Loader2 className="h-4 w-4 animate-spin" />
+                      <Loader2 className="h-4 w-4 animate-spin" aria-hidden />
                     ) : (
-                      <Circle className="h-4 w-4" />
+                      <Circle className="h-4 w-4" aria-hidden />
                     )}
                   </span>
                   <div className="flex-1 min-w-0">
@@ -243,7 +243,7 @@ export function OnboardingChecklist() {
                           className="text-sm font-medium hover:underline inline-flex items-center gap-1"
                         >
                           {idx + 1}. {step.label}
-                          <ExternalLink className="h-3 w-3 opacity-50" />
+                          <ExternalLink className="h-3 w-3 opacity-50" aria-hidden />
                         </Link>
                         <p className="mt-0.5 text-xs text-muted-foreground">{step.description}</p>
                         {auto && (
@@ -265,7 +265,7 @@ export function OnboardingChecklist() {
                           onClick={() => toggleManual(step.id)}
                         >
                           {saving === step.id ? (
-                            <Loader2 className="h-3.5 w-3.5 animate-spin" />
+                            <Loader2 className="h-3.5 w-3.5 animate-spin" aria-hidden />
                           ) : manual ? (
                             'Mark incomplete'
                           ) : (