refactor: Add SpecBinding record for per-spec server state

Author: thced

src/main/java/com/retailsvc/http/internal/SpecBinding.java

@@ -0,0 +1,38 @@
+package com.retailsvc.http.internal;
+
+import com.retailsvc.http.RequestHandler;
+import com.retailsvc.http.SchemeValidator;
+import com.retailsvc.http.spec.Spec;
+import com.retailsvc.http.validate.DefaultValidator;
+import java.util.Map;
+
+/**
+ * Bundles everything the server needs to serve one OpenAPI spec: the spec itself, the handler map
+ * keyed by {@code operationId}, the security-scheme validator map, and the derived {@link Router}
+ * and {@link DefaultValidator}. One {@code SpecBinding} drives exactly one {@code HttpContext}.
+ */
+public record SpecBinding(
+    Spec spec,
+    Map<String, RequestHandler> handlers,
+    Map<String, SchemeValidator> securityValidators,
+    DefaultValidator validator,
+    Router router) {
+
+  public SpecBinding {
+    handlers = Map.copyOf(handlers);
+    securityValidators = Map.copyOf(securityValidators);
+  }
+
+  /** Builds a binding by deriving the {@link Router} and {@link DefaultValidator} from the spec. */
+  public static SpecBinding of(
+      Spec spec,
+      Map<String, RequestHandler> handlers,
+      Map<String, SchemeValidator> securityValidators) {
+    return new SpecBinding(
+        spec,
+        handlers,
+        securityValidators,
+        new DefaultValidator(spec::resolveSchema),
+        new Router(spec.operations()));
+  }
+}