[ko] Sync /docs/concepts/architecture with the latest en content

**This is a Feature Request**

**What would you like to be added**

Sync Korean documents under `/docs/concepts/architecture` with the latest English content.
This umbrella issue will track the progress of updates to multiple outdated files.

Target files include:

- [ ] /docs/concepts/architecture/cloud-controller.md
https://kubernetes.io/ko/docs/concepts/architecture/cloud-controller/

- [ ] /docs/concepts/architecture/_index.md
https://kubernetes.io/ko/docs/concepts/architecture/_index/
- [ ] /docs/concepts/architecture/controller.md
https://kubernetes.io/ko/docs/concepts/architecture/controller/
- [ ] /docs/concepts/architecture/leases.md
https://kubernetes.io/ko/docs/concepts/architecture/leases/
- [ ] /docs/concepts/architecture/nodes.md
https://kubernetes.io/ko/docs/concepts/architecture/nodes/
- [ ] /docs/concepts/architecture/self-healing.md
https://kubernetes.io/ko/docs/concepts/architecture/self-healing/

- [ ] /docs/concepts/architecture/garbage-collection.md
https://kubernetes.io/ko/docs/concepts/architecture/garbage-collection/

Small fixes will be grouped in one PR, and the rest will be submitted separately.

**Why is this needed**

Some pages under `/docs/concepts/architecture` are outdated compared to the latest English version.
To maintain consistency and accuracy, these documents need to be synchronized with the upstream content.

**Comments**

/language ko