feat(commands): add app state dispatcher foundation

commands/index.ts

@@ -1 +1,19 @@
 export type { Command, CommandContext } from "./command";
+export type { CommandDispatcher, Dispatch } from "./dispatcher";
+export { createCommandDispatcher } from "./dispatcher";
+export type { CommandRegistry } from "./registry";
+export { createCommandRegistry } from "./registry";
+export {
+  viewportCommands,
+  viewportPanCommand,
+  viewportResetCommand,
+  viewportSetSizeCommand,
+  viewportSetZoomCommand,
+  viewportZoomAroundPointCommand,
+} from "./viewport";
+export type {
+  ViewportPanPayload,
+  ViewportSetSizePayload,
+  ViewportSetZoomPayload,
+  ViewportZoomAroundPointPayload,
+} from "./viewport";