Add embedded Swagger UI page with auto-injected JWT auth

- New /swagger route with lazy-loaded SwaggerPage that initializes
  swagger-ui-dist and injects the session JWT via requestInterceptor
- Move API link from primary nav to navRight utility area (pill style)
- Code-split swagger chunk (~1.4 MB) so main bundle stays lean

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

ui/src/swagger-ui-dist.d.ts

@@ -0,0 +1,10 @@
+declare module 'swagger-ui-dist/swagger-ui-es-bundle.js' {
+  interface SwaggerUIOptions {
+    url?: string;
+    domNode?: HTMLElement;
+    deepLinking?: boolean;
+    requestInterceptor?: (req: Record<string, unknown>) => Record<string, unknown>;
+    [key: string]: unknown;
+  }
+  export default function SwaggerUI(options: SwaggerUIOptions): void;
+}