feat(rspack): support reusing binding artifact from rspack CI

When sourceRunId is provided, download pre-built binding from rspack's
CI workflow instead of rebuilding from scratch (~18 min saved).
Falls back to local Rust build when sourceRunId is empty (manual dispatch).

Amp-Thread-ID: https://ampcode.com/threads/T-019d4391-1316-72c3-a295-7a86e5a54a3d
Co-authored-by: Amp <amp@ampcode.com>

Author: fi3ework

.github/workflows/rspack-ecosystem-ci-from-commit.yml

@@ -56,6 +56,16 @@ on:
         required: true
         type: string
         default: "precoded"
+      sourceRunId:
+        description: "workflow run ID from rspack CI that produced the binding artifact"
+        required: false
+        type: string
+        default: ""
+      sourceRepo:
+        description: "rspack repository that produced the binding artifact"
+        required: false
+        type: string
+        default: "web-infra-dev/rspack"
 
 jobs:
   get-runner-labels:
@@ -68,7 +78,29 @@ jobs:
     runs-on: ${{ fromJSON(needs.get-runner-labels.outputs.LINUX_RUNNER_LABELS) }}
     steps:
       - uses: actions/checkout@v4
-      - uses: ./.github/actions/prepare-rspack-binding
+
+      # Path A: download pre-built binding from rspack CI
+      - name: Download binding from rspack CI
+        if: inputs.sourceRunId != ''
+        uses: actions/download-artifact@v4
+        with:
+          name: bindings-x86_64-unknown-linux-gnu
+          path: workspace/rspack-binding
+          repository: ${{ inputs.sourceRepo }}
+          run-id: ${{ inputs.sourceRunId }}
+          github-token: ${{ secrets.RSPACK_REPO_ACTIONS_READ_ONLY }}
+
+      - name: Upload normalized binding artifact
+        if: inputs.sourceRunId != ''
+        uses: actions/upload-artifact@v4
+        with:
+          name: binding-linux-x64-gnu
+          path: workspace/rspack-binding/*.node
+
+      # Path B: build binding from scratch (manual dispatch)
+      - name: Build binding from scratch
+        if: inputs.sourceRunId == ''
+        uses: ./.github/actions/prepare-rspack-binding
         with:
           repository: ${{ inputs.repo }}
           ref: ${{ inputs.commitSHA }}