Validates a Custom Elements Manifest against the official, vendored CEM JSON
Schema (draft-07) using ajv, so the output is guaranteed spec-conformant with
precise, path-level errors — beyond the structural subset that
validateManifest checks by hand.
ajv is an optional dependency (loaded lazily, like Playwright/axe). When it
is not installed this throws SchemaValidatorUnavailableError; callers
that want a soft fallback should catch it and use validateManifest alone.
Validates a Custom Elements Manifest against the official, vendored CEM JSON Schema (draft-07) using ajv, so the output is guaranteed spec-conformant with precise, path-level errors — beyond the structural subset that
validateManifestchecks by hand.ajv is an optional dependency (loaded lazily, like Playwright/axe). When it is not installed this throws SchemaValidatorUnavailableError; callers that want a soft fallback should catch it and use
validateManifestalone.