feat(js): m09 input, app, runtime, browser, main, index.html and smoke test

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

js/solutions/app.js

@@ -0,0 +1,24 @@
+import { Action } from './model.js'
+import { update } from './game.js'
+import { newGame } from './spawn.js'
+import { view } from './view.js'
+import { map as mapIO, randomSeed, drawScene } from './io.js'
+import { keyDowns, interval, map, filterMap, merge, scan, startWith } from './stream.js'
+import { keyToAction } from './input.js'
+
+export const TICK_MS = 150
+
+// Everything that can happen to the game: a Tick every TICK_MS, and a Turn for each steering key.
+export const classicActions = merge(
+  map(interval(TICK_MS), () => Action.Tick),
+  filterMap(keyDowns, keyToAction))
+
+// Actions folded into game states. startWith puts the initial state first so it is drawn right away.
+export const states = (seed, actions) =>
+  startWith(scan(actions, update, newGame(seed)), newGame(seed))
+
+export const render = (state) => drawScene(view(state))
+
+// The whole program as a value: get a seed, then turn the stream of states into a stream of drawings.
+// Nothing runs here; runtime.js interprets it.
+export const main = mapIO(randomSeed, (seed) => map(states(seed, classicActions), render))