bug: package.json version out of sync with VERSION file on main

PR #360 bumped `VERSION` to `0.11.10.0` but missed `package.json` (still `0.11.9.0`).

The existing test catches it:

```
gen-skill-docs > package.json version matches VERSION file
Expected: "0.11.10.0"
Received: "0.11.9.0"
```

One-line fix: #400