feat(admin): per-port email/Documenso/branding/reminder settings + invitations

Centralizes everything operators need to configure into the admin panel,
each setting per-port with env fallback.

New admin pages
- /admin              landing page linking to every admin section as a card
- /admin/email        FROM name+address, reply-to, signature/footer HTML,
                      optional SMTP host/port/user/pass override
- /admin/documenso    API URL+key override, EOI Documenso template ID,
                      default EOI pathway (documenso-template vs inapp),
                      "Test connection" button
- /admin/branding     logo URL, primary color, app name, email
                      header/footer HTML
- /admin/reminders    port-level defaults for new interests +
                      port-wide daily-digest delivery window
- /admin/invitations  send / list / resend / revoke CRM invitations

Per-user reminder digest
- /notifications/preferences gains a Reminder digest card:
  immediate / daily / weekly / off, with HH:MM, day-of-week,
  IANA timezone fields. Stored in user_profiles.preferences.reminders.

Plumbing
- port-config.ts typed accessors (getPortEmailConfig, getPortDocumensoConfig,
  getPortBrandingConfig, getPortReminderConfig) — settings → env fallback.
- sendEmail accepts optional portId; resolves From/SMTP from settings
  when supplied.
- documensoFetch + downloadSignedPdf accept optional portId; each public
  function takes it through. checkDocumensoHealth() backs the test button.
- crm-invite.service gains listCrmInvites / revokeCrmInvite / resendCrmInvite
  with audit-log entries (revoke_invite, resend_invite added to AuditAction).
- AdminLandingPage card grid + shared SettingsFormCard component to remove
  per-page form boilerplate.

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

src/app/(dashboard)/[portSlug]/admin/branding/page.tsx

@@ -0,0 +1,69 @@
+import {
+  SettingsFormCard,
+  type SettingFieldDef,
+} from '@/components/admin/shared/settings-form-card';
+
+const FIELDS: SettingFieldDef[] = [
+  {
+    key: 'branding_app_name',
+    label: 'App name',
+    description: 'Shown in the email subject prefix and the in-app header.',
+    type: 'string',
+    placeholder: 'Port Nimara CRM',
+    defaultValue: '',
+  },
+  {
+    key: 'branding_logo_url',
+    label: 'Logo URL',
+    description:
+      'Public HTTPS URL of the logo used in email headers and the branded auth shell. Recommended size: 240×80 PNG with transparent background.',
+    type: 'string',
+    placeholder: 'https://example.com/logo.png',
+    defaultValue: '',
+  },
+  {
+    key: 'branding_primary_color',
+    label: 'Primary color',
+    description: 'Used for buttons and links in transactional email templates.',
+    type: 'color',
+    defaultValue: '#1e293b',
+  },
+  {
+    key: 'branding_email_header_html',
+    label: 'Email header HTML',
+    description: 'Optional HTML rendered above each email body. Leave blank to use the default.',
+    type: 'html',
+    defaultValue: '',
+  },
+  {
+    key: 'branding_email_footer_html',
+    label: 'Email footer HTML',
+    description: 'Optional HTML rendered at the very bottom of each email (above the signature).',
+    type: 'html',
+    defaultValue: '',
+  },
+];
+
+export default function BrandingSettingsPage() {
+  return (
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-2xl font-semibold">Branding</h1>
+        <p className="text-sm text-muted-foreground">
+          Logo, primary color, app name, and email header/footer HTML used by the branded auth shell
+          and outgoing email templates.
+        </p>
+      </div>
+      <SettingsFormCard
+        title="Identity"
+        description="App name, logo, and primary color."
+        fields={FIELDS.slice(0, 3)}
+      />
+      <SettingsFormCard
+        title="Email branding"
+        description="HTML fragments rendered around every transactional email."
+        fields={FIELDS.slice(3)}
+      />
+    </div>
+  );
+}