Add GitHub Actions workflow for JP loadingbg sync

Author: stephensund

.github/workflows/jp-loadingbg.yml

@@ -0,0 +1,76 @@
+name: JP loadingbg sync
+
+permissions:
+  contents: write   # ✅ 必须，否则 Release 会失败
+
+on:
+  schedule:
+    - cron: "0 3 * * *"   # UTC 03:00 (≈ JST 12:00)
+  workflow_dispatch:
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install azlassets
+        run: |
+          python -m pip install --upgrade pip
+          pip install azlassets
+
+      - name: Download JP loadingbg assets
+        run: |
+          python -m downloader JP
+
+      # -------- 拉取上一次 Release 的 full 包 --------
+      - name: Download last full snapshot (if exists)
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          API="https://api.github.com/repos/${{ github.repository }}/releases/tags/jp-loadingbg-latest"
+
+          if curl -fsSL -H "Authorization: token $GITHUB_TOKEN" "$API" > release.json; then
+            URL=$(jq -r '.assets[] | select(.name=="loadingbg_full.zip") | .browser_download_url' release.json)
+            if [ -n "$URL" ]; then
+              curl -L -o loadingbg_full.zip "$URL"
+              unzip -q loadingbg_full.zip
+              mv current_loadingbg last_loadingbg
+            fi
+          fi
+
+      - name: Collect loadingbg
+        run: |
+          python scripts/collect_loadingbg.py
+
+      - name: Diff and zip
+        run: |
+          bash scripts/diff_and_zip.sh
+
+      - name: Generate meta
+        run: |
+          echo "client=JP" > meta.txt
+          echo "updated_at=$(date -u)" >> meta.txt
+
+      # -------- 发布 / 更新固定 Release --------
+      - name: Publish Release
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: jp-loadingbg-latest
+          name: JP loadingbg latest
+          body: |
+            Automated daily sync of JP loadingbg assetbundles.
+
+            - Full snapshot: loadingbg_full.zip
+            - Incremental update: loadingbg_diff.zip
+          files: |
+            loadingbg_full.zip
+            loadingbg_diff.zip
+            meta.txt
+``