fix(client): restore tiles variable for zone tint loop in fog_state

The merge of visual and client branches dropped the `tiles` variable
declaration. The client branch refactored bounds calculation to use
`visible_positions`, but the visual branch's zone tint loop still
iterates over `visible_tiles` for zone_id data.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/scripts/autoloads/fog_state.gd

@@ -181,6 +181,9 @@ func update_from_state() -> void:
 	# 3. Zone tint: write zone temperature color for currently visible tiles.
 	#    Zone data is stable (tile zone never changes) so we only write on first sight.
 	#    Data persists in _tint_bytes across frames and across resizes.
+	#    visible_tiles carries zone_id per tile (populated from snapshot "tiles" or
+	#    "visible_tiles" with type field — see game_state.gd apply_snapshot).
+	var tiles := GameState.visible_tiles
 	var tint_dirty := false
 	for tile in tiles:
 		if not tile is Dictionary or not tile.has("x") or not tile.has("y"):