~anthropic/claude-sonnet-latest → B (70:30)

Side B fixes a real bug (inconsistent canonical URL forms for the tilde ontology root causing sibling-rank/child-lookup mismatches), adds targeted unit and integration tests plus a browser regression test, and documents the invariant clearly. Side A mostly removes an unrelated demo feature and adds a settlement-worker/caching refactor that is reasonable but riskier and less obviously validated (no new tests for correctness of the batching/caching logic), making B's fix more clearly a lasting correctness improvement.