ci(version): add version sync check between package.json and Cargo.toml (#277)

Add automated verification that package.json and cli/Cargo.toml versions
stay in sync. This prevents version drift between the npm package and
Rust CLI binary.

- Add CI job to check version sync on push/PR
- Update pre-commit hook to sync versions automatically
- Update ci:version script to include version sync step
- Add check-version-sync.js script for CI validation

.github/workflows/ci.yml

@@ -7,6 +7,16 @@ on:
     branches: [main]
 
 jobs:
+  version-sync:
+    name: Version Sync Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check version sync
+        run: node scripts/check-version-sync.js
+
   typescript:
     name: TypeScript (Node ${{ matrix.node-version }})
     runs-on: ubuntu-latest