Implement admin ports and system settings management

- Port CRUD: list, create, update with branding, currency, timezone
- System settings: upsert key-value pairs per port with known settings UI
  (AI feature flags, invoice discount, pipeline weights, berth rules)
- Settings manager with toggle switches, number inputs, and JSON editors
- Replace both stub pages with real implementations

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -1,16 +1,5 @@
+import { PortList } from '@/components/admin/ports/port-list';
+
 export default function PortManagementPage() {
-  return (
-    <div className="space-y-6">
-      <div>
-        <h1 className="text-2xl font-bold text-foreground">Port Management</h1>
-        <p className="text-muted-foreground">Manage port locations and configurations</p>
-      </div>
-      <div className="flex flex-col items-center justify-center rounded-lg border border-dashed p-12">
-        <p className="text-lg font-medium text-muted-foreground">Coming in Layer 2</p>
-        <p className="text-sm text-muted-foreground">
-          This feature will be implemented in the next phase.
-        </p>
-      </div>
-    </div>
-  );
+  return <PortList />;
 }

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

@@ -1,16 +1,5 @@
+import { SettingsManager } from '@/components/admin/settings/settings-manager';
+
 export default function SystemSettingsPage() {
-  return (
-    <div className="space-y-6">
-      <div>
-        <h1 className="text-2xl font-bold text-foreground">System Settings</h1>
-        <p className="text-muted-foreground">Configure system-wide settings</p>
-      </div>
-      <div className="flex flex-col items-center justify-center rounded-lg border border-dashed p-12">
-        <p className="text-lg font-medium text-muted-foreground">Coming in Layer 2</p>
-        <p className="text-sm text-muted-foreground">
-          This feature will be implemented in the next phase.
-        </p>
-      </div>
-    </div>
-  );
+  return <SettingsManager />;
 }