fix(audit-wave-9): standardize on Sheet for previews; doctrine in CLAUDE.md

Swap the one outlier (client-interests-tab.tsx) from Vaul Drawer to
Sheet side=right so every detail-preview surface uses the same
primitive. Document the doctrine: Sheet for side panels on both desktop
and mobile; Vaul Drawer reserved for mobile-only bottom-sheet UX
(currently just MoreSheet).

Closes ui/ux M11.

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

src/lib/email/templates/inquiry-client-confirmation.tsx

@@ -12,6 +12,7 @@ export interface InquiryClientConfirmationData {
 
 interface RenderOpts {
   branding?: BrandingShell | null;
+  subject?: string | null;
 }
 
 function ClientConfirmationBody({
@@ -61,9 +62,11 @@ export async function inquiryClientConfirmation(
   const { firstName, mooringNumber, contactEmail } = data;
   const portName = data.portName ?? 'Port Nimara';
   const berthText = mooringNumber ? `Berth ${mooringNumber}` : `a ${portName} Berth`;
-  const subject = mooringNumber
-    ? `Thank You for Your Interest in Berth ${mooringNumber}`
-    : `Thank You for Your Interest in a ${portName} Berth`;
+  const subject = overrides?.subject?.trim()
+    ? overrides.subject
+    : mooringNumber
+      ? `Thank You for Your Interest in Berth ${mooringNumber}`
+      : `Thank You for Your Interest in a ${portName} Berth`;
   const accent = brandingPrimaryColor(overrides?.branding);
 
   const body = await render(