Add HTTP Basic authentication to the agent's API. Update OpenAPI specification to include security requirements and modify the server handler to enforce authentication. Introduce default admin credentials for access control.

lib/openapi/spec_test.go

@@ -14,10 +14,16 @@ func TestSpec(t *testing.T) {
 	if _, ok := paths["/api/v1/status"]; !ok {
 		t.Fatal("missing /api/v1/status")
 	}
+	if _, ok := spec["security"]; !ok {
+		t.Fatal("missing security")
+	}
 	components, ok := spec["components"].(map[string]any)
 	if !ok {
 		t.Fatal("missing components")
 	}
+	if _, ok := components["securitySchemes"]; !ok {
+		t.Fatal("missing securitySchemes")
+	}
 	schemas, ok := components["schemas"].(map[string]any)
 	if !ok || len(schemas) < 10 {
 		t.Fatalf("expected schemas, got %d", len(schemas))