refactor: split casino.go, dedup helpers, remove audit docs

1 files changed, 17 insertions, 4 deletions

diff --git a/internal/game/render_map.go b/internal/game/render_map.go
index e8d7cea..ff36344 100644
--- a/internal/game/render_map.go
+++ b/internal/game/render_map.go
@@ -57,10 +57,23 @@ type mapGraph struct {
 const playerZ = 0
 
 func buildGraph(g *Game, sess *net.Session, startRoomID int) *mapGraph {
-	rg := world.BuildGrid(startRoomID, func(id int) (*world.Room, bool) {
-		return loadRoom(g, id)
-	}, nil, func(fromID int, dir world.ExitDir, targetID int) bool {
-		room, ok := loadRoom(g, fromID)
+	// BuildGrid calls load for the BFS node AND edgeInclude re-loads the same
+	// room for its exit check, so memoize per render: without this every room
+	// reachable from the player is os.ReadFile+yaml.Unmarshal'd twice per map.
+	cache := make(map[int]*world.Room)
+	load := func(id int) (*world.Room, bool) {
+		if r, ok := cache[id]; ok {
+			return r, true
+		}
+		r, ok := loadRoom(g, id)
+		if !ok {
+			return nil, false
+		}
+		cache[id] = r
+		return r, true
+	}
+	rg := world.BuildGrid(startRoomID, load, nil, func(fromID int, dir world.ExitDir, targetID int) bool {
+		room, ok := load(fromID)
 		if !ok {
 			return true
 		}