follow stab55_2, 1. reduce CGS setup peak allocation by reusing the source matrix; 2. preserve transfer correctness under tier0/tier1 tests; 3. document that c128 large-lattice setup remains limited by the full double hierarchy. [opencode].
follow stab55_2, 1. reduce CGS setup peak allocation by reusing the source matrix; 2. preserve transfer correctness under tier0/tier1 tests; 3. document that c128 large-lattice setup remains limited by the full double hierarchy. [opencode].