v4.1.1

Changed

• Graph-tool directive escalated from "prefer" to MUST (BILL-633, BILL-634, BILL-636, BILL-638). Measured across six fleet runs: 1,262+ grep/Read discovery calls and zero graph calls despite tools being available and every repo indexed. New reference doc with the discovery/content split, mandatory list_projects gate in every worker launch prompt, concrete example calls in all 8 worker skills.

Fixed

• Universal §8 tracking-dir resolution used a hardcoded path instead of the three-tier $TRACKING_DIR ladder.
• check_hooks matched on marker substring instead of exact command path (BILL-633).

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Also includes the missing v4.1.0 changelog entry (adversary single-round, parallel gates, /code-review agent-invocability correction).