feat: add branch strategy via BranchStrategy class

Stages now gated by branch:
- PR-*: test only
- feature/*: test + build/push + helm bump + git push
- develop/main/release/hotfix: test + build/push only

Jenkinsfile

@@ -1,35 +1,15 @@
+@Library('homelab') _
+
+import vn.fireflylab.pipeline.BranchStrategy
+
 pipeline {
     agent {
         kubernetes {
-            yaml """
-apiVersion: v1
-kind: Pod
-spec:
-  containers:
-  - name: node
-    image: node:18-slim
-    command:
-    - sleep
-    args:
-    - infinity
-  - name: docker
-    image: docker:dind
-    securityContext:
-      privileged: true
-    env:
-    - name: DOCKER_TLS_CERTDIR
-      value: ""
-    args:
-    - --insecure-registry=harbor-core.harbor.svc.cluster.local
-"""
+            yaml homelabK8sAgent(withTools: true)
         }
     }
 
     environment {
-        APP_NAME        = 'tictactoe'
-        HARBOR_REGISTRY = 'harbor-core.harbor.svc.cluster.local'
-        HARBOR_PROJECT  = 'library'
-        IMAGE           = "${HARBOR_REGISTRY}/${HARBOR_PROJECT}/${APP_NAME}"
         DOCKER_HOST = 'tcp://localhost:2375'
     }
 
@@ -37,28 +17,34 @@ spec:
         stage('Install & Test') {
             steps {
                 container('node') {
-                    sh 'npm install'
-                    sh 'npm test'
+                    runNodeTest()
                 }
             }
         }
 
         stage('Build & Push Image') {
+            when { expression { BranchStrategy.shouldBuildImage(env.BRANCH_NAME) } }
             steps {
-                script {
-                    def imageTag = "${env.BRANCH_NAME.replaceAll('/', '-')}-${UUID.randomUUID().toString().take(8)}"
                 container('docker') {
-                        withCredentials([usernamePassword(
-                            credentialsId: 'harbor-credentials',
-                            usernameVariable: 'HARBOR_USER',
-                            passwordVariable: 'HARBOR_PASS'
-                        )]) {
-                            sh """
-                                docker login ${HARBOR_REGISTRY} -u \${HARBOR_USER} -p \${HARBOR_PASS}
-                                docker build -t ${IMAGE}:${imageTag} .
-                                docker push ${IMAGE}:${imageTag}
-                            """
-                        }
+                    script {
+                        def tag = BranchStrategy.imageTag(env.BRANCH_NAME)
+                        env.IMAGE_TAG = tag
+                        dockerBuildPush(appName: 'tictactoe', tag: tag)
+                    }
+                }
+            }
+        }
+
+        stage('Bump Helm Chart') {
+            when { expression { BranchStrategy.shouldBumpChart(env.BRANCH_NAME) } }
+            steps {
+                container('tools') {
+                    script {
+                        bumpHelmChart(imageTag: env.IMAGE_TAG)
+                        gitCommitPush(
+                            files: ['manifest/helm/Chart.yaml', 'manifest/helm/values.yaml'],
+                            message: "ci: bump tictactoe chart to ${env.IMAGE_TAG}"
+                        )
                     }
                 }
             }