The activation persist step was writing wm_weight=0 for every node not reached
by the current BFS fan-out. This destroyed working memory accumulated by
MCP-layer activations within one tick of the awareness loop firing on an empty
inbox. ACT-R and Soar treat spreading activation as additive: absent seeds
contribute zero spread, not a zero override of existing WM state.
Fix: non-reached nodes now decay by ENGRAM_WM_DECAY (0.7) per activation call
rather than being immediately zeroed. A hard floor of 0.005 clears near-zero
values to prevent infinite decay tails. Reached nodes behave unchanged.
will.anderson
db7dae8236