feat: register homelab shared library in Jenkins JCasC

Adds global pipeline library 'homelab' pointing to
gitea.fireflylab.cc/duynguyen/homelab-jenkins-shared-libs.git
on main branch. Uses gitea-credentials for auth.

manifest/jenkins/values.yaml

@@ -597,6 +597,20 @@ controller:
     # - https://acme.org/jenkins.yaml
     # -- List of Jenkins Config as Code scripts
     configScripts:
+      global-libraries: |
+        unclassified:
+          globalLibraries:
+            libraries:
+            - name: "homelab"
+              defaultVersion: "main"
+              implicit: false
+              allowVersionOverride: true
+              retriever:
+                modernSCM:
+                  scm:
+                    git:
+                      remote: "https://gitea.fireflylab.cc/duynguyen/homelab-jenkins-shared-libs.git"
+                      credentialsId: "gitea-credentials"
       pipeline-credentials: |
         credentials:
           system: