feat(commands): add app state dispatcher foundation

commands/registry.ts

@@ -0,0 +1,22 @@
+import type { Command } from "./command";
+
+export type CommandRegistry = {
+  get(id: string): Command<unknown> | undefined;
+  list(): Command<unknown>[];
+};
+
+export function createCommandRegistry(commands: Command<unknown>[]): CommandRegistry {
+  const byId = new Map<string, Command<unknown>>();
+
+  for (const command of commands) {
+    if (byId.has(command.id)) {
+      throw new Error(`Duplicate command id: ${command.id}`);
+    }
+    byId.set(command.id, command);
+  }
+
+  return {
+    get: (id) => byId.get(id),
+    list: () => [...byId.values()],
+  };
+}