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

package.json

@@ -34,7 +34,7 @@
     "test:watch": "vitest",
     "postinstall": "node scripts/postinstall.js",
     "changeset": "changeset",
-    "ci:version": "changeset version && pnpm install --no-frozen-lockfile",
+    "ci:version": "changeset version && pnpm run version:sync && pnpm install --no-frozen-lockfile",
     "ci:publish": "pnpm run version:sync && pnpm run build && changeset publish"
   },
   "keywords": [