chore(hooks): let stories import webkit assets under camelCase bindings

[gabriel-lisboa-azion]

Summary

• The story-source binding check expects every @aziontech/webkit/* default import to be a PascalCase component name, so a story could not import an asset file at all (ddos-protection.svg has no valid PascalCase binding). assets/ now joins utils/ and styles/ as non-component subpaths the check skips.

How to test

1. node .claude/hooks/__tests__/run.mjs → the new "asset import keeps its camelCase binding (exit 0)" case passes; import Chip from '@aziontech/webkit/chips' still blocks.
2. node .claude/hooks/validate-story-source.mjs --all → every story file complies.

Notes

• No release (tooling only). Needed by the marketing asset stack (feat(webkit): add the logo and illustration asset library #1047 and the Assets docs PR), which import assets in stories.
• legacy button is whitelisted and new component without spec blocks fail on main already; unrelated to this change.