fix(hooks): dispatch specialistStart/Stop lifecycle hooks

[Ayush7614]

Summary

specialistStart / specialistStop are documented in EXTENDING.md, accepted by zero hooks add, and present in the hooks package — but the specialist runtime never dispatches them. Matcher support is also inconsistent: docs say specialist matchers are allowed, while LoadConfig rejected them.

Proposed fix

• Dispatch advisory specialistStart/Stop hooks from specialist accounting
• Allow specialist-name matchers (matching EXTENDING.md)
• Wire the hooks dispatcher into specialist tools after startup builds it

Related work

Implementation ready on branch feat/specialist-lifecycle-hooks.

Notes for maintainers

Please add issue-approved if this scope is accepted so the linked community PR can proceed under CONTRIBUTING.md.