feat(actions): PullRequest merge action (#24823)

Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

resource_customizations/promoter.argoproj.io/PullRequest/actions/action_test.yaml

@@ -0,0 +1,17 @@
+discoveryTests:
+- inputPath: testdata/open-pr.yaml
+  result:
+  - name: merge
+    disabled: false
+    iconClass: fa fa-fw fa-code-merge
+    displayName: Merge PR
+- inputPath: testdata/merged-pr.yaml
+  result:
+  - name: merge
+    disabled: true
+    iconClass: fa fa-fw fa-code-merge
+    displayName: Merge PR
+actionTests:
+- action: merge
+  inputPath: testdata/open-pr.yaml
+  expectedOutputPath: testdata/merged-pr.yaml

resource_customizations/promoter.argoproj.io/PullRequest/actions/discovery.lua

@@ -0,0 +1,8 @@
+local actions = {}
+
+actions["merge"] = {
+    ["iconClass"] = "fa fa-fw fa-code-merge",
+    ["disabled"] = obj.spec.state ~= "open",
+    ["displayName"] = "Merge PR"
+}
+return actions

resource_customizations/promoter.argoproj.io/PullRequest/actions/merge/action.lua

@@ -0,0 +1,2 @@
+obj.spec.state = "merged"
+return obj

resource_customizations/promoter.argoproj.io/PullRequest/actions/testdata/merged-pr.yaml

@@ -0,0 +1,37 @@
+apiVersion: promoter.argoproj.io/v1alpha1
+kind: PullRequest
+metadata:
+  finalizers:
+    - pullrequest.promoter.argoporoj.io/finalizer
+  labels:
+    promoter.argoproj.io/change-transfer-policy: promotion-strategy-wave-0-west-24b5855
+    promoter.argoproj.io/environment: wave-0-west
+    promoter.argoproj.io/promotion-strategy: promotion-strategy
+  name: test-org-test-repo-wave-0-west-next-wave-0-west-ac5b3e8c
+  namespace: gitops-promoter
+spec:
+  commit:
+    message: >
+      Promote 89752 to `wave/0/west`
+  description: >-
+    This PR is promoting the environment branch `wave/0/west` which is currently
+    on dry sha bc0df509c35ec9ee4268f3fb0b514bafe26f0ee5 to dry sha
+    897529bb51f3b8ac7482071d26d2947c1f25dc16.
+  gitRepositoryRef:
+    name: test-repo
+  sourceBranch: wave/0/west-next
+  state: merged
+  targetBranch: wave/0/west
+  title: Promote 89752 to `wave/0/west`
+status:
+  conditions:
+    - lastTransitionTime: '2025-10-01T18:18:26Z'
+      message: Reconciliation succeeded
+      observedGeneration: 5
+      reason: ReconciliationSuccess
+      status: 'True'
+      type: Ready
+  id: '2986'
+  prCreationTime: '2025-10-01T18:18:25Z'
+  state: open
+  url: https://git.example.com/test-org/test-repo/pull/2986

resource_customizations/promoter.argoproj.io/PullRequest/actions/testdata/open-pr.yaml

@@ -0,0 +1,37 @@
+apiVersion: promoter.argoproj.io/v1alpha1
+kind: PullRequest
+metadata:
+  finalizers:
+    - pullrequest.promoter.argoporoj.io/finalizer
+  labels:
+    promoter.argoproj.io/change-transfer-policy: promotion-strategy-wave-0-west-24b5855
+    promoter.argoproj.io/environment: wave-0-west
+    promoter.argoproj.io/promotion-strategy: promotion-strategy
+  name: test-org-test-repo-wave-0-west-next-wave-0-west-ac5b3e8c
+  namespace: gitops-promoter
+spec:
+  commit:
+    message: >
+      Promote 89752 to `wave/0/west`
+  description: >-
+    This PR is promoting the environment branch `wave/0/west` which is currently
+    on dry sha bc0df509c35ec9ee4268f3fb0b514bafe26f0ee5 to dry sha
+    897529bb51f3b8ac7482071d26d2947c1f25dc16.
+  gitRepositoryRef:
+    name: test-repo
+  sourceBranch: wave/0/west-next
+  state: open
+  targetBranch: wave/0/west
+  title: Promote 89752 to `wave/0/west`
+status:
+  conditions:
+    - lastTransitionTime: '2025-10-01T18:18:26Z'
+      message: Reconciliation succeeded
+      observedGeneration: 5
+      reason: ReconciliationSuccess
+      status: 'True'
+      type: Ready
+  id: '2986'
+  prCreationTime: '2025-10-01T18:18:25Z'
+  state: open
+  url: https://git.example.com/test-org/test-repo/pull/2986