docs: group cloud storage components under architecture/cloud-storage

Move Ceph, Rook, Chorus, Arbiter, and Prysm into a dedicated
`architecture/cloud-storage/` section so the sidebar reflects the
logical relationship between these components — they are all part of
the same storage stack rather than independent top-level topics.

Add `cloud-storage/index.md` as the section landing page with a
summary table linking all five components and describing their roles.

Update `architecture/index.md` to point to the new group instead of
linking Ceph directly.

Internal cross-links between the moved files are unaffected since they
are siblings within the same folder.

Author: senolcolak

docs/architecture/arbiter.md …cs/architecture/cloud-storage/arbiter.mddocs/architecture/arbiter.md renamed to docs/architecture/cloud-storage/arbiter.md docs/architecture/arbiter.md renamed to docs/architecture/cloud-storage/arbiter.md

@@ -0,0 +1,15 @@
+---
+title: Cloud Storage
+---
+
+# Cloud Storage
+
+CobaltCore's cloud storage layer is built on [Ceph](./ceph.md), an open-source, distributed storage system that delivers object, block, and file storage in a single unified platform. The surrounding components manage its lifecycle, replication, observability, and high-availability configuration.
+
+| Component | Role |
+|-----------|------|
+| [Ceph](./ceph.md) | Distributed storage engine |
+| [Rook](./rook.md) | Kubernetes operator that automates Ceph deployment and management |
+| [Chorus](./chorus.md) | Data replication across object storage systems |
+| [Arbiter](./arbiter.md) | External arbiter monitors for Ceph quorum in stretched clusters |
+| [Prysm](./prysm.md) | Observability CLI for Ceph clusters and RGW deployments |

docs/architecture/ceph.md docs/architecture/cloud-storage/ceph.mddocs/architecture/ceph.md renamed to docs/architecture/cloud-storage/ceph.md

@@ -13,4 +13,4 @@ CobaltCore is built on top of OpenStack and IronCore, leveraging their capabilit
 - **Greenhouse**: The monitoring and management tool that provides insights into the health and performance of the CobaltCore environment.
 - [**HA Service**](./cluster#ha-service): The high availability service that ensures critical workloads remain operational even in the event of failures.
 - [**Cortex**](./cortex): Smart initial placement and scheduling service for compute, storage, and network in cloud-native cloud environments.
-- [**Ceph**](./ceph): An all-in-one storage system that provides object, block, and file storage and delivers extraordinary scalability. 
+- [**Cloud Storage**](./cloud-storage): Ceph-based distributed storage stack including Rook, Chorus, Arbiter, and Prysm for lifecycle management, replication, quorum, and observability.