feat: update sync workflow and README for KV storage support

.github/workflows/sync-upstream.yml

@@ -4,6 +4,9 @@ on:
   schedule:
     - cron: "0 3 * * *"
   workflow_dispatch:
+  push:
+    branches:
+      - main
 
 permissions:
   contents: write
@@ -17,12 +20,45 @@ jobs:
         with:
           fetch-depth: 0
 
-      - run: |
-          git remote add upstream https://github.com/shuaiplus/nodewarden.git || true
+      - name: Configure git
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+      - name: Sync main from upstream
+        run: |
+          git remote add upstream https://github.com/shuaiplus/NodeWarden.git || true
           git fetch upstream
 
-          # 强制让当前分支完全等于 upstream
+          git checkout main
           git reset --hard upstream/main
-
-          # 强制推送
           git push origin main --force
+
+      - name: Rebuild kv from main
+        run: |
+          git fetch origin main kv || true
+          git checkout -B kv origin/main
+
+          python - <<'PY'
+from pathlib import Path
+
+path = Path("wrangler.toml")
+text = path.read_text(encoding="utf-8")
+old = """[[r2_buckets]]
+binding = "ATTACHMENTS"
+bucket_name = "nodewarden-attachments"
+"""
+new = """[[kv_namespaces]]
+binding = "ATTACHMENTS_KV"
+id = "REPLACE_WITH_KV_NAMESPACE_ID"
+"""
+
+if old not in text:
+    raise SystemExit("Expected R2 block not found in wrangler.toml")
+
+path.write_text(text.replace(old, new, 1), encoding="utf-8")
+PY
+
+          git add wrangler.toml
+          git commit -m "chore(kv): sync from main" || echo "No changes"
+          git push origin kv --force