[ci] allow manual workflow dispatch to do version bumping on core branches (rather than just on main) (#6117)

## Summary

Added configurable base branch selection to version bump workflows,
enabling patch releases from `core/*` branches via GitHub Actions UI.

## Changes

- **What**: Extended [workflow_dispatch
inputs](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflow_dispatch)
with `branch` parameter for both main frontend and desktop-ui version
bump workflows
- **Validation**: Added branch existence check that lists available
`core/*` branches on error
- **Workflow modifications**:
- `release-version-bump.yaml`: Checkout and create PRs targeting
user-specified branch
- `version-bump-desktop-ui.yaml`: Same behavior for desktop-ui releases

## Review Focus

Branch validation logic correctly handles both local (`refs/heads/`) and
remote (`refs/remotes/origin/`) refs. Default value preserves backward
compatibility for release sheriffs unfamiliar with new feature.

## Use Case

Previously, patch releases from `core/1.29` required manual version
bumping. Now maintainers can trigger from Actions UI with dropdown
selections.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6117-ci-allow-manual-workflow-dispatch-to-do-version-bumping-on-core-branches-rather-than-j-2906d73d365081cba3aff46471206a9e)
by [Unito](https://www.unito.io)

.github/workflows/release-version-bump.yaml

@@ -15,6 +15,11 @@ on:
         required: false
         default: ''
         type: string
+      branch:
+        description: 'Base branch to bump (e.g., main, core/1.29, core/1.30)'
+        required: true
+        default: 'main'
+        type: string
 
 jobs:
   bump-version:
@@ -26,6 +31,24 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v5
+        with:
+          ref: ${{ github.event.inputs.branch }}
+          fetch-depth: 0
+
+      - name: Validate branch exists
+        run: |
+          BRANCH="${{ github.event.inputs.branch }}"
+          if ! git show-ref --verify --quiet "refs/heads/$BRANCH" && ! git show-ref --verify --quiet "refs/remotes/origin/$BRANCH"; then
+            echo "❌ Branch '$BRANCH' does not exist"
+            echo ""
+            echo "Available core branches:"
+            git branch -r | grep 'origin/core/' | sed 's/.*origin\//  - /' || echo "  (none found)"
+            echo ""
+            echo "Main branch:"
+            echo "  - main"
+            exit 1
+          fi
+          echo "✅ Branch '$BRANCH' exists"
 
       - name: Install pnpm
         uses: pnpm/action-setup@v4
@@ -59,7 +82,9 @@ jobs:
           title: ${{ steps.bump-version.outputs.NEW_VERSION }}
           body: |
             ${{ steps.capitalised.outputs.capitalised }} version increment to ${{ steps.bump-version.outputs.NEW_VERSION }}
+
+            **Base branch:** `${{ github.event.inputs.branch }}`
           branch: version-bump-${{ steps.bump-version.outputs.NEW_VERSION }}
-          base: main
+          base: ${{ github.event.inputs.branch }}
           labels: |
             Release

.github/workflows/version-bump-desktop-ui.yaml

@@ -14,6 +14,11 @@ on:
         required: false
         default: ''
         type: string
+      branch:
+        description: 'Base branch to bump (e.g., main, core/1.29, core/1.30)'
+        required: true
+        default: 'main'
+        type: string
 
 jobs:
   bump-version-desktop-ui:
@@ -26,8 +31,25 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
         with:
+          ref: ${{ github.event.inputs.branch }}
+          fetch-depth: 0
           persist-credentials: false
 
+      - name: Validate branch exists
+        run: |
+          BRANCH="${{ github.event.inputs.branch }}"
+          if ! git show-ref --verify --quiet "refs/heads/$BRANCH" && ! git show-ref --verify --quiet "refs/remotes/origin/$BRANCH"; then
+            echo "❌ Branch '$BRANCH' does not exist"
+            echo ""
+            echo "Available core branches:"
+            git branch -r | grep 'origin/core/' | sed 's/.*origin\//  - /' || echo "  (none found)"
+            echo ""
+            echo "Main branch:"
+            echo "  - main"
+            exit 1
+          fi
+          echo "✅ Branch '$BRANCH' exists"
+
       - name: Install pnpm
         uses: pnpm/action-setup@v4
         with:
@@ -64,8 +86,10 @@ jobs:
           title: desktop-ui ${{ steps.bump-version.outputs.NEW_VERSION }}
           body: |
             ${{ steps.capitalised.outputs.capitalised }} version increment for @comfyorg/desktop-ui to ${{ steps.bump-version.outputs.NEW_VERSION }}
+
+            **Base branch:** `${{ github.event.inputs.branch }}`
           branch: desktop-ui-version-bump-${{ steps.bump-version.outputs.NEW_VERSION }}
-          base: main
+          base: ${{ github.event.inputs.branch }}
           labels: |
             Release