Scaffold proxy-operator with kubebuilder v4.15.0 (go/v4)

Bootstraps the empty repo into a kubebuilder go/v4 project: group
crawl.example.com, version v1alpha1, kind Proxy (namespaced). Keeps the
existing module path and preserves the repo's Go/testing/changelog
conventions from CLAUDE.md untouched.

Drops the scaffolded GitHub Actions workflows since the remote is Gitea,
not GitHub. Everything else is default kubebuilder output, unmodified,
so later diffs stay reviewable against a known baseline.

Full implementation plan: docs/plans/2026-08-07-1747-proxy-operator.md

Co-Authored-By: Claude <noreply@anthropic.com>

hack/boilerplate.go.txt

@@ -0,0 +1,15 @@
+/*
+Copyright YEAR.
+
+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.
+*/