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/email/page.tsx

@@ -0,0 +1,101 @@
+import {
+  SettingsFormCard,
+  type SettingFieldDef,
+} from '@/components/admin/shared/settings-form-card';
+
+const FIELDS: SettingFieldDef[] = [
+  {
+    key: 'email_from_name',
+    label: 'From name',
+    description: 'Display name shown in the From: header on outgoing email.',
+    type: 'string',
+    placeholder: 'Port Nimara',
+    defaultValue: '',
+  },
+  {
+    key: 'email_from_address',
+    label: 'From address',
+    description: 'Sender email address. Falls back to SMTP_FROM env when blank.',
+    type: 'string',
+    placeholder: 'noreply@example.com',
+    defaultValue: '',
+  },
+  {
+    key: 'email_reply_to',
+    label: 'Reply-to address',
+    description: 'Optional Reply-To: header for replies (e.g. sales@example.com).',
+    type: 'string',
+    placeholder: 'sales@example.com',
+    defaultValue: '',
+  },
+  {
+    key: 'email_signature_html',
+    label: 'Default signature (HTML)',
+    description: 'Appended to the bottom of system-generated emails.',
+    type: 'html',
+    placeholder: '<p>—<br>The Port Nimara team</p>',
+    defaultValue: '',
+  },
+  {
+    key: 'email_footer_html',
+    label: 'Email footer (HTML)',
+    description: 'Legal/contact footer rendered at the very bottom of all emails.',
+    type: 'html',
+    placeholder: '<p style="font-size:11px;color:#888;">© Port Nimara · ul. ...</p>',
+    defaultValue: '',
+  },
+  {
+    key: 'smtp_host_override',
+    label: 'SMTP host override',
+    description: 'Optional. Falls back to SMTP_HOST env when blank.',
+    type: 'string',
+    placeholder: 'mail.example.com',
+    defaultValue: '',
+  },
+  {
+    key: 'smtp_port_override',
+    label: 'SMTP port override',
+    description: 'Optional. Falls back to SMTP_PORT env when blank.',
+    type: 'number',
+    placeholder: '587',
+    defaultValue: null,
+  },
+  {
+    key: 'smtp_user_override',
+    label: 'SMTP username override',
+    description: 'Optional. Falls back to SMTP_USER env when blank.',
+    type: 'string',
+    defaultValue: '',
+  },
+  {
+    key: 'smtp_pass_override',
+    label: 'SMTP password override',
+    description: 'Optional. Stored in plain text — only set when overriding env credentials.',
+    type: 'password',
+    defaultValue: '',
+  },
+];
+
+export default function EmailSettingsPage() {
+  return (
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-2xl font-semibold">Email Settings</h1>
+        <p className="text-sm text-muted-foreground">
+          Per-port outgoing email configuration. SMTP credentials and the From address default to
+          environment variables when these fields are blank.
+        </p>
+      </div>
+      <SettingsFormCard
+        title="From address & signature"
+        description="Identity headers and shared HTML used by system-generated emails."
+        fields={FIELDS.slice(0, 5)}
+      />
+      <SettingsFormCard
+        title="SMTP transport overrides"
+        description="Optional per-port SMTP credentials. Leave blank to use the global env defaults."
+        fields={FIELDS.slice(5)}
+      />
+    </div>
+  );
+}