Add Desktop UI npm publishing workflows (#5915)

## Summary

Adds automated npm publishing for @comfyorg/desktop-ui package with
version management and release workflows.

- Ref: #5912

## Changes

- **What**: Three GitHub Actions workflows for desktop-ui npm publishing
automation

### Two functions

1. Bump action - Just creates a version bump PR for `desktop-ui`
2. Publish action - Can be run manually - essentially a function with
params / void return

### One automation

- Watches for matching commits, then calls the Publish action with
pre-filled details

## Review Focus

Security hardening and workflow correctness.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5915-Add-Desktop-UI-npm-publishing-workflows-2826d73d365081d9b7f8d7f752536ceb)
by [Unito](https://www.unito.io)

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

@@ -0,0 +1,71 @@
+name: Version Bump Desktop UI
+
+on:
+  workflow_dispatch:
+    inputs:
+      version_type:
+        description: 'Version increment type'
+        required: true
+        default: 'patch'
+        type: 'choice'
+        options: [patch, minor, major, prepatch, preminor, premajor, prerelease]
+      pre_release:
+        description: Pre-release ID (suffix)
+        required: false
+        default: ''
+        type: string
+
+jobs:
+  bump-version-desktop-ui:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v5
+        with:
+          node-version: '24.x'
+          cache: 'pnpm'
+
+      - name: Bump desktop-ui version
+        id: bump-version
+        env:
+          VERSION_TYPE: ${{ github.event.inputs.version_type }}
+          PRE_RELEASE: ${{ github.event.inputs.pre_release }}
+        run: |
+          pnpm -C apps/desktop-ui version "$VERSION_TYPE" --preid "$PRE_RELEASE" --no-git-tag-version
+          NEW_VERSION=$(node -p "require('./apps/desktop-ui/package.json').version")
+          echo "NEW_VERSION=$NEW_VERSION" >> $GITHUB_OUTPUT
+
+      - name: Format PR string
+        id: capitalised
+        env:
+          VERSION_TYPE: ${{ github.event.inputs.version_type }}
+        run: |
+          echo "capitalised=${VERSION_TYPE@u}" >> $GITHUB_OUTPUT
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e
+        with:
+          token: ${{ secrets.PR_GH_TOKEN }}
+          commit-message: '[release] Increment desktop-ui to ${{ steps.bump-version.outputs.NEW_VERSION }}'
+          title: desktop-ui ${{ steps.bump-version.outputs.NEW_VERSION }}
+          body: |
+            ${{ steps.capitalised.outputs.capitalised }} version increment for @comfyorg/desktop-ui to ${{ steps.bump-version.outputs.NEW_VERSION }}
+          branch: desktop-ui-version-bump-${{ steps.bump-version.outputs.NEW_VERSION }}
+          base: main
+          labels: |
+            Release
+