ARCCHR0003 — Reactor must not reach the default event log

A reactor can return events to Chronicle. The rule finds direct this.<field>.eventLog.append(...) or appendMany(...) (including .transactional) when the field is initialized or assigned earlier in the same method with this.client.getEventStore(...) or this.runtime.getStore(...). It does not report fields initialized from other.getEventStore('elsewhere'), uninitialized store fields, reads, outbox writes, callbacks inside handlers, or helper calls. The reactor decorator must come from @cratis/chronicle or @cratis/chronicle/reactors. The SDK has no reactor DI ownership contract: even for a matching this.client/this.runtime field the rule cannot prove that client or store belongs to the reactor.

// Instead of: await this.store.eventLog.append(id, new FollowedUp());
return new FollowedUp();

This is an analog of the .NET warning, not a complete data-flow analysis. Other direct SDK appends still need review. Chronicle code analysis maps the other diagnostics.