feat(smart-proxy): add typed Rust config serialization and regex header contract coverage

test/test.route-utils.ts

@@ -537,6 +537,31 @@ tap.test('Route Matching - routeMatchesHeaders', async () => {
     'X-Custom-Header': 'value'
   })).toBeFalse();
 
+  const regexHeaderRoute: IRouteConfig = {
+    match: {
+      domains: 'example.com',
+      ports: 80,
+      headers: {
+        'Content-Type': /^application\/(json|problem\+json)$/i,
+      }
+    },
+    action: {
+      type: 'forward',
+      targets: [{
+        host: 'localhost',
+        port: 3000
+      }]
+    }
+  };
+
+  expect(routeMatchesHeaders(regexHeaderRoute, {
+    'Content-Type': 'Application/Problem+Json',
+  })).toBeTrue();
+
+  expect(routeMatchesHeaders(regexHeaderRoute, {
+    'Content-Type': 'text/html',
+  })).toBeFalse();
+
   // Route without header matching should match any headers
   const noHeaderRoute: IRouteConfig = {
     match: { ports: 80, domains: 'example.com' },