[codex] optimize professional editor interactions

[youngwinds]

Summary

• Refactor practices/professional editor interaction code into smaller drag/drop, slot target, payload, and token-menu utilities.
• Replace the old config field editor path with SlotFieldToken and focused overlay/token behavior.
• Split drag/drop styling into drop target and drop indicator styles.
• Add focused tests for drag payloads, drop logic, overlay positioning, token menus, slot target models, and editor component behavior.
• Update changeset config for the professional practice package scope.

Impact

This PR changes the professional practice editor implementation and tests. It does not change public package APIs.

Validation

• pnpm --filter professional run test
• pnpm --filter professional run lint
• pnpm --filter professional run typecheck
• pnpm --filter professional run build
• pnpm run lint:check
• pnpm run typecheck
• pre-push typecheck hook passed