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/components/admin/documenso/documenso-test-button.tsx

@@ -0,0 +1,64 @@
+'use client';
+
+import { useState } from 'react';
+import { Loader2, CheckCircle2, XCircle } from 'lucide-react';
+import { toast } from 'sonner';
+
+import { Button } from '@/components/ui/button';
+import { apiFetch } from '@/lib/api/client';
+
+interface HealthResponse {
+  ok: boolean;
+  status?: number;
+  error?: string;
+}
+
+export function DocumensoTestButton() {
+  const [pending, setPending] = useState(false);
+  const [result, setResult] = useState<HealthResponse | null>(null);
+
+  async function runTest() {
+    setPending(true);
+    setResult(null);
+    try {
+      const res = await apiFetch<{ data: HealthResponse }>('/api/v1/admin/documenso/health', {
+        method: 'POST',
+      });
+      setResult(res.data);
+      if (res.data.ok) {
+        toast.success(`Documenso reachable (HTTP ${res.data.status ?? 200})`);
+      } else {
+        toast.error(
+          res.data.error ?? `Documenso responded with HTTP ${res.data.status ?? 'unknown'}`,
+        );
+      }
+    } catch (err) {
+      const message = err instanceof Error ? err.message : 'Test failed';
+      setResult({ ok: false, error: message });
+      toast.error(message);
+    } finally {
+      setPending(false);
+    }
+  }
+
+  return (
+    <div className="flex items-center gap-3">
+      {result &&
+        (result.ok ? (
+          <span className="flex items-center text-xs text-green-600">
+            <CheckCircle2 className="mr-1 h-3.5 w-3.5" />
+            HTTP {result.status}
+          </span>
+        ) : (
+          <span className="flex items-center text-xs text-destructive">
+            <XCircle className="mr-1 h-3.5 w-3.5" />
+            {result.error ?? `HTTP ${result.status}`}
+          </span>
+        ))}
+      <Button variant="outline" onClick={runTest} disabled={pending}>
+        {pending && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+        Test connection
+      </Button>
+    </div>
+  );
+}