fix: adjust prod release flow to support release branch lookup

.github/actions/get-latest-pr-number/action.yml

@@ -8,6 +8,9 @@ inputs:
   token:
     description: Specify token (GH or PAT), instead of inheriting one from the calling workflow
     default: ${{ github.token }}
+  release_branch:
+    description: Specify the release branch to get the latest PR number from, like `release/myrelease`. Outside of PRs you need to manually provide this otherwise it will be an empty string.
+    default: ${{ github.pull_request.head.ref }}
 
 outputs:
   pr:
@@ -22,8 +25,13 @@ runs:
       run: |
         git fetch origin
 
-        release_branch="${{ github.event.pull_request.head.ref }}"
-        echo "Detected release branch: $release_branch"
+        release_branch="${{ inputs.release_branch }}"
+        echo "Configured release branch as: $release_branch"
+
+        if ! git show-ref --verify --quiet refs/remotes/origin/$release_branch; then
+          echo "Release branch $release_branch does not exist in the repository."
+          exit 1
+        fi
 
         latest_pr=$(git log origin/$release_branch --pretty=format:'%s' | grep -oP '(?<=#)\d+' | head -n 1)
 

.github/workflows/merge-main.yml → .github/workflows/release-main.yml

@@ -1,18 +1,10 @@
-name: Merge
+name: Release To Production
 
 on:
-  push:
-    branches: [main]
-    paths-ignore:
-      - "*.md"
-      - ".github/**"
-      - ".github/graphics/**"
-      - "!.github/workflows/**"
   workflow_dispatch:
     inputs:
-      pr_no:
-        description: "PR-numbered container set to deploy"
-        type: number
+      release_branch:
+        description: "Specify the release branch to get the latest PR number from, like `release/myrelease`"
         required: true
 
 concurrency:
@@ -28,10 +20,17 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 1
     steps:
+      - name: Verify Is Main Branch
+        if: github.event_name == 'workflow_dispatch' && github.ref != 'refs/heads/main'
+        run: |
+          echo "This workflow should not be triggered with workflow_dispatch on a branch other than main"
+          exit 1
       - uses: actions/checkout@v4
       - name: Get Latest PR Number in release branch
         id: latest-pr
         uses: ./.github/actions/get-latest-pr-number
+        with:
+          release_branch: ${{ github.event.inputs.release_branch }}
       - name: Set PR Output
         run: echo "pr=${{ steps.latest-pr.outputs.pr }}" >> $GITHUB_OUTPUT