chore(rename): railiance-bootstrap → railiance-cluster

Update all operational references to reflect the new repo name per
ADR-003 (OAS S2 Cluster Runtime). Historical text in docs preserved.
Gitea remote URL updated locally (Gitea repo rename is a manual step).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

QUICKSTART.md

@@ -10,8 +10,8 @@ This guide is written for newcomers who want to set up their very first Railianc
 Clone this repository locally and enter it:
 
 ```bash
-git clone https://<your-gitea-domain>/<org-or-user>/railiance-bootstrap.git
-cd railiance-bootstrap
+git clone https://<your-gitea-domain>/<org-or-user>/railiance-cluster.git
+cd railiance-cluster
 ```
 
 (Replace `<your-gitea-domain>` and `<org-or-user>` with your setup.)