Implement Task

Web workflow v2

When invoked inside an active $start-workflow session, read the web event adapter and use it for questions, progress, decisions and handoffs. It replaces chat-only delivery and later-turn invocation requirements with matching web events; all scope, artifact ownership and verification rules below remain in force. A next-stage button authorizes only that named stage. Standalone/chat use stays supported. Delegated utilities and verification workers report to the parent event consumer.

Implement exactly one selected task and leave a focused, reviewable diff.