feat: Replace shell script with idiomatic go generate for code gen

Makefile

@@ -64,7 +64,7 @@ lint: ## Lint the code
 
 .PHONY: generate # Regenerate code
 generate:
-	./hack/generate.sh
+	go generate ./...
 
 .PHONY: all
 all: fmt test lint generate

generate.go

@@ -0,0 +1,24 @@
+/*
+Copyright 2025 The CDEvents Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+// This file contains go:generate directives for code generation.
+// Run `go generate` from the project root to regenerate all code.
+
+package main
+
+//go:generate go run tools/generator.go --resources .