Added AGENTS.md and CLAUDE.md (strimzi#12633)

Signed-off-by: Paolo Patierno <ppatierno@live.com>

Author: ppatierno

.gitignore

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 # Claude configuration
 .claude/
-CLAUDE.md
 .mcp.json

AGENTS.md

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+# Strimzi Kafka Operator
+
+Strimzi provides a way to run Apache Kafka® clusters on Kubernetes and OpenShift using the Operator pattern.
+It simplifies the deployment and management of Kafka clusters, including topics, users, connectors, and more.
+
+See [README.md](README.md) for project overview, quick starts, and community information.
+
+## Architecture
+
+Multi-module Maven project.
+
+### Requirements
+
+- **Java**: Java 21
+- **Build tools**: Maven 3.5+, make, bash
+- **Helm**: Helm 3 (for Helm chart packaging and testing)
+- **Container runtime**: Docker or Podman (use `DOCKER_CMD=podman` for Podman)
+- **Kubernetes cluster**: Required for integration/system tests (minikube, kind, or remote cluster)
+
+### Key Dependencies
+
+- Kafka client and Fabric8 Kubernetes client versions: See `pom.xml`
+- Supported Kafka versions (for cluster deployment): See `kafka-versions.yaml`
+
+### Modules
+
+| Module | Purpose                                                            |
+|--------|--------------------------------------------------------------------|
+| `cluster-operator/` | Main operator managing Kafka clusters                              |
+| `topic-operator/` | Manages Kafka topics via KafkaTopic CRs                            |
+| `user-operator/` | Manages Kafka users and ACLs via KafkaUser CRs                     |
+| `api/` | CRD definitions and API models (Kafka, KafkaTopic, KafkaUser, etc.) |
+| `operator-common/` | Shared operator code and utilities                                 |
+| `kafka-agent/` | Java agent running inside Kafka containers (broker config, metrics) |
+| `tracing-agent/` | OpenTelemetry tracing support                                      |
+| `certificate-manager/` | TLS certificate management and CA handling                         |
+| `kafka-init/` | Kafka container initialization logic                               |
+| `crd-generator/` | Generates CRDs from `api` module via Java annotations              |
+| `crd-annotations/` | Annotations for CRD generation                                     |
+| `config-model/` | Kafka configuration models utility classes                         |
+| `config-model-generator/` | Generates Kafka configuration models                               |
+| `v1-api-conversion/` | Conversion tool from v1beta2 to v1 CRDs                    |
+| `mockkube/` | Mock Kubernetes for unit testing                                   |
+| `test/` | Test utilities and helpers                                         |
+| `systemtest/` | End-to-end system tests                                            |
+
+## Contributing
+
+- **Commit sign-off (DCO)** (REQUIRED on all commits): always use `git commit -s`
+  - If forgotten: `git commit --amend -s` to fix last commit
+  - CI will fail without sign-off
+  - More info: [CONTRIBUTING.md](CONTRIBUTING.md)
+
+- **Code style**: Enforced by checkstyle (runs in CI on all PRs)
+  - Config: `.checkstyle/checkstyle.xml`
+  - Run locally: `mvn checkstyle:check`
+  - CI will fail if checkstyle errors are found
+
+## Developer Notes
+
+### Common Development Tasks
+
+**Building:**
+- Build project: `make all` (compiles Java, runs tests, builds Docker images)
+- Clean build artifacts: `make clean`
+- Customize Maven behavior: Use `MVN_ARGS` environment variable
+  - Skip all tests: `MVN_ARGS=-DskipTests make all`
+  - Skip integration tests only: `MVN_ARGS=-DskipITs make all`
+- Build specific module: Run `make all` or `make clean` from module directory (`MVN_ARGS` works here too)
+
+**Testing:**
+- Unit tests only: `mvn test`
+- Unit + integration tests: `mvn verify`
+- System tests (requires Kubernetes cluster): see [TESTING.md](development-docs/TESTING.md)
+
+**CRD Changes:** If you changed anything in the `api/` module:
+1. Run `make all` in the `api/` module to update generated files
+2. Run `make crd_install` to update derived CRDs in:
+   - `api/src/test/resources/crds/`
+   - `packaging/install/cluster-operator/`
+   - `packaging/helm-charts/helm3/strimzi-kafka-operator/crds/`
+
+**Generated Code** (Never edit directly):
+- Sundrio builders/fluent classes (generated from annotations)
+- Config Model JSONs (generated from Kafka source)
+- Files in `target/` directories or marked `@Generated`
+
+**Container Images:**
+- Built via `docker-images/` Makefiles
+- Base images in `docker-images/base/`
+- Use `DOCKER_CMD=podman` to use Podman instead of Docker
+- Environment variables for custom registry:
+  - `DOCKER_ORG`: your registry organization/username (e.g., Docker Hub or Quay.io username, default: `$USER`)
+  - `DOCKER_REGISTRY`: registry to use (e.g., `docker.io`, `quay.io`, default: `docker.io`)
+  - `DOCKER_TAG`: image tag (default: `latest`)
+  - `DOCKER_ARCHITECTURE`: target architecture for container images (e.g., `amd64`, `arm64`)
+
+## Documentation
+
+User-facing documentation is in `documentation/` folder (AsciiDoc format):
+- **Overview guide**: Key concepts and features
+- **Deploying and Managing guide**: Deployment instructions and best practices
+- **API Reference**: Detailed configuration reference
+
+For contributing to documentation, see the documentation related [README.md](documentation/README.md).

CLAUDE.md

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+@AGENTS.md