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>

.gitignore

@@ -0,0 +1,30 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+bin/*
+Dockerfile.cross
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Go workspace file
+go.work
+
+# Kubernetes Generated files - skip generated files, except for vendored files
+!vendor/**/zz_generated.*
+
+# editor and IDE paraphernalia
+.idea
+.vscode
+*.swp
+*.swo
+*~
+
+# Kubeconfig might contain secrets
+*.kubeconfig