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>

.custom-gcl.yml

@@ -0,0 +1,11 @@
+# This file configures golangci-lint with module plugins.
+# When you run 'make lint', it will automatically build a custom golangci-lint binary
+# with all the plugins listed below.
+#
+# See: https://golangci-lint.run/plugins/module-plugins/
+version: v2.12.2
+plugins:
+  # logcheck validates structured logging calls and parameters (e.g., balanced key-value pairs)
+  - module: "sigs.k8s.io/logtools"
+    import: "sigs.k8s.io/logtools/logcheck/gclplugin"
+    version: latest