refactor: decouple github.ts and enhance type safety + test coverage

.github/workflows/sync.yml

@@ -0,0 +1,31 @@
+name: Daily Stargazer Sync
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+  workflow_dispatch:
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5
+        with:
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020
+        with:
+          node-version: 20
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run sync script
+        run: node scripts/sync-stargazers.mjs
+        env:
+          CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+          CLOUDFLARE_DATABASE_NAME: ${{ secrets.CLOUDFLARE_DATABASE_NAME }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}