feat: migrated map (and bfs) to full 3D instead of individual 2D maps on different planes.

1 files changed, 5 insertions, 0 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 4f547ab..789b361 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -165,3 +165,8 @@ Full field reference in `item/item.go`. Key fields: equip_slot, weapon_type, att
 - **Tick subscriber ordering**: `AdvanceActions`, combat subscriptions, mob attack subscriptions,
   and hazard ticks are independent subscribers without priority guarantees. A trigger completing
   and a mob landing a hit on the same tick have non-deterministic ordering.
+- **3D map BFS cost**: `buildGraph()` does a full 3D BFS across the entire reachable world on every
+  map render (`map`/`look`/move). For large worlds (10k+ rooms) this could become expensive. Options:
+  (a) cache the graph keyed by player room and invalidate on world edits (`dig`/`room insert`/`undig`),
+  (b) prune by visited rooms (revert to horizontal-only expansion from unvisited), or (c) compute z-level
+  assignments once at startup and use precomputed plane membership.