Implement main game as a mod

common/protocol.ts

@@ -1,6 +1,7 @@
 // messages sent between the client and the server, as json over a websocket
 import type { Faces } from "./constants.ts";
 import type { ItemData } from "./inventory.ts";
+import type { ModListing } from "./mod_loader.ts";
 
 export const AIR_ID = "bworld:air";
 
@@ -58,7 +59,11 @@ export type ServerMessage =
 	| {
 		type: "welcome";
 		id: string;
+		// the server may change the name asked for, like alice to alice2
+		name: string;
 		seed: string;
+		// in load order, the client loads them before joining the world
+		mods: ModListing[];
 		players: PlayerInfo[];
 		changes: BlockChange[];
 		spawn: { x: number; y: number; z: number; yaw: number; pitch: number };
@@ -70,6 +75,7 @@ export type ServerMessage =
 	// also sent to the player who caused it, which corrects anything their client predicted wrong
 	| { type: "set_block"; x: number; y: number; z: number; id: string }
 	| { type: "chat"; from?: string; text: string }
+	| { type: "teleport"; x: number; y: number; z: number }
 	| { type: "container"; container: ContainerKey; items: (ItemData | null)[] }
 	| { type: "cursor"; item: ItemData | null }
 	| { type: "open_screen"; layout: ScreenLayout; properties: Record<string, number> }