World/Actor stress-test sims: the Actor learns most gaps from the World, so verify them

When stress-testing a written proposal with two agents (a World agent role-plays stakeholders and events; an Actor agent tries to carry out the plan and logs every point where the document left it stuck), check where each answer came from. In one run, about 41 of 63 gap entries were resolved by taking the World agent at its word, with only a handful of real document or web lookups. The most dramatic "the plan is wrong" findings were World assertions that the source material did not support (one even contradicted the project notes). Fixes: (1) tell the Actor to verify every factual World assertion that changes its plan against real sources, and to tag each gap world-asserted, sourced or assumed; (2) have the World cite or mark every factual claim it invents; (3) run a separate skeptic pass that rates each driving claim SUPPORTED, CONTRADICTED or INVENTED before using the gap list to revise the document. The method is still useful: the categories of gaps (missing actors, numbers, steps, rules) were real even when individual World facts were not.