ci(hot-cluster): add ipi diagnostics-only mode to setup workflow

Select infrastructure_type=ipi to run IPI prerequisite checks
(VPC, COS, DNS, IAM Identity, resource groups, auth policies)
without creating any resources. All common steps are skipped.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: galkremer1

.github/workflows/ibmc-cluster-setup.yml

@@ -4,13 +4,14 @@ on:
   workflow_dispatch:
     inputs:
       infrastructure_type:
-        description: 'Infrastructure type: classic or vpc'
+        description: 'Infrastructure type: classic, vpc, or ipi (ipi = diagnostics only)'
         required: true
         default: 'classic'
         type: choice
         options:
           - classic
           - vpc
+          - ipi
       cluster_name:
         description: 'Cluster name'
         required: true
@@ -90,6 +91,7 @@ jobs:
           if-no-files-found: warn
 
       - name: Check for existing cluster
+        if: inputs.infrastructure_type != 'ipi'
         id: check_cluster
         run: |
           if ibmcloud oc cluster get --cluster "${CLUSTER_NAME}" &>/dev/null; then
@@ -271,31 +273,36 @@ jobs:
             --disable-outbound-traffic-protection
 
       # ──────────────────────────────────────────────────────────────────────
-      # Common steps (both classic and VPC converge here)
+      # Common steps (both classic and VPC converge here; skipped for ipi)
       # ──────────────────────────────────────────────────────────────────────
       - name: Wait for cluster to be ready to use
+        if: inputs.infrastructure_type != 'ipi'
         run: |
           ./ci-scripts/check-roks-cluster-state.sh
 
       - name: Install oc client from cluster version
+        if: inputs.infrastructure_type != 'ipi'
         run: |
           CLUSTER_JSON="$(ibmcloud oc cluster get --cluster "${CLUSTER_NAME}" --output json)"
           export CLUSTER_JSON
           bash ./ci-scripts/install-oc-client.sh
 
       - name: Configure kubeconfig
+        if: inputs.infrastructure_type != 'ipi'
         run: |
           ibmcloud oc cluster config --cluster "${CLUSTER_NAME}" --admin
           oc cluster-info
           oc get nodes -o wide
 
       - name: Install HCO
+        if: inputs.infrastructure_type != 'ipi'
         env:
           KVM_EMULATION: ${{ inputs.kvm_emulation }}
         run: |
           ./ci-scripts/install-hco.sh
 
       - name: Verify ARC secrets
+        if: inputs.infrastructure_type != 'ipi'
         run: |
           HAS_APP=$([ -n "${{ secrets.ARC_GITHUB_APP_ID }}" ] && [ -n "${{ secrets.ARC_GITHUB_APP_INSTALL_ID }}" ] && [ -n "${{ secrets.ARC_GITHUB_APP_PRIVATE_KEY }}" ] && echo "yes" || echo "no")
           HAS_PAT=$([ -n "${{ secrets.ARC_GITHUB_PAT }}" ] && echo "yes" || echo "no")
@@ -310,6 +317,7 @@ jobs:
           echo "ARC secrets are present."
 
       - name: Build ARC runner image
+        if: inputs.infrastructure_type != 'ipi'
         id: build_runner
         env:
           OC_VERSION: '4.20'
@@ -318,6 +326,7 @@ jobs:
           echo "image_ref=${IMAGE_REF}" >> "$GITHUB_OUTPUT"
 
       - name: Install ARC
+        if: inputs.infrastructure_type != 'ipi'
         env:
           ARC_CONFIG_URL: 'https://github.com/${{ github.repository }}'
           ARC_APP_ID: ${{ secrets.ARC_GITHUB_APP_ID }}
@@ -331,10 +340,12 @@ jobs:
           ./ci-scripts/arc/install-runner-scale-set.sh
 
       - name: Install CI environment controller
+        if: inputs.infrastructure_type != 'ipi'
         run: |
           ./ci-scripts/ci-env/install-ci-env-controller.sh
 
       - name: Verify cluster health
+        if: inputs.infrastructure_type != 'ipi'
         env:
           GITHUB_REPOSITORY: ${{ github.repository }}
         run: |