feat(branding): wire per-port branding through every transactional email + auth shell (R2-H15)

Multi-tenant branding admin (/admin/branding) was saving 5 settings
that no code read — every port's emails shipped Port Nimara's logo
and color regardless. Now wired end-to-end:

New shared infrastructure:
- src/lib/email/shell.ts — renderShell() + brandingPrimaryColor()
  helpers; takes BrandingShell { logoUrl, primaryColor,
  emailHeaderHtml, emailFooterHtml }, falls back to Port Nimara
  defaults when null.
- src/lib/email/branding-resolver.ts — getBrandingShell(portId)
  thin wrapper over getPortBrandingConfig() that returns null on
  error / missing portId so senders never break on misconfig.

All 6 transactional templates refactored to use renderShell + the
shared accent color; portName now flows through every template
(crm-invite, portal activation/reset, both inquiries, both
residential templates, notification digest).

All 6 senders pass branding via getBrandingShell:
- portal-auth.service.ts (activation + reset)
- crm-invite.service.ts (resend path; create-invite has no portId
  yet so falls through to defaults)
- email worker (inquiry confirmation + sales notification)
- residential-inquiries route (client confirmation + sales alert)
- notification-digest.service.ts (digest)

BrandedAuthShell takes an optional `branding` prop with logoUrl +
appName (parent page server-fetches via getPortBrandingConfig).
Defaults to Port Nimara if omitted, so single-tenant deployments
are unaffected.

1175/1175 vitest passing.

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

src/lib/queue/workers/email.ts

@@ -30,7 +30,12 @@ export const emailWorker = new Worker(
           await import('@/lib/email/templates/inquiry-client-confirmation');
         const { sendEmail } = await import('@/lib/email/index');
         const { resolveSubject } = await import('@/lib/email/resolve-subject');
-        const email = inquiryClientConfirmation({ firstName, mooringNumber, contactEmail });
+        const { getBrandingShell } = await import('@/lib/email/branding-resolver');
+        const branding = await getBrandingShell(portId);
+        const email = inquiryClientConfirmation(
+          { firstName, mooringNumber, contactEmail, portName },
+          { branding },
+        );
         const subject = await resolveSubject({
           key: 'inquiry_client_confirmation',
           portId,
@@ -60,13 +65,19 @@ export const emailWorker = new Worker(
           await import('@/lib/email/templates/inquiry-sales-notification');
         const { sendEmail } = await import('@/lib/email/index');
         const { resolveSubject } = await import('@/lib/email/resolve-subject');
-        const notification = inquirySalesNotification({
-          fullName,
-          email,
-          phone,
-          mooringNumber,
-          crmUrl,
-        });
+        const { getBrandingShell } = await import('@/lib/email/branding-resolver');
+        const branding = await getBrandingShell(portId);
+        const notification = inquirySalesNotification(
+          {
+            fullName,
+            email,
+            phone,
+            mooringNumber,
+            crmUrl,
+            portName,
+          },
+          { branding },
+        );
         const subject = await resolveSubject({
           key: 'inquiry_sales_notification',
           portId,