validatePackages
Attempt to import() every package listed in the skill class’s
REQUIRED_PACKAGES static array. Returns the list of packages that failed to
import (empty array means everything is available). Python parity:
validate_packages() at core/skill_base.py:112-124.
Logs an error listing every missing package when the result is non-empty.
For a boolean check, use hasAllPackages(). Because
the TS version uses dynamic import(), this method is async.
Returns
Promise<string[]> — array of package names that failed to import. Empty when
all packages are available.