Bundle brainstorm server dependencies instead of requiring npm install

Vendor node_modules into the repo so the brainstorm server works
immediately on fresh plugin installs without needing npm at runtime.

skills/brainstorming/scripts/node_modules/side-channel-map/index.d.ts

@@ -0,0 +1,15 @@
+declare namespace getSideChannelMap {
+	type Channel<K, V> = {
+		assert: (key: K) => void;
+		has: (key: K) => boolean;
+		get: (key: K) => V | undefined;
+		set: (key: K, value: V) => void;
+		delete: (key: K) => boolean;
+	};
+}
+
+declare function getSideChannelMap<K, V>(): getSideChannelMap.Channel<K, V>;
+
+declare const x: false | typeof getSideChannelMap;
+
+export = x;