Add play.html: the whole game in one file you can open from a disk

.github/workflows/ci.yml

@@ -85,6 +85,18 @@ jobs:
       - name: Drive the page with a real cursor and keyboard
         run: node web/test/input.mjs --url http://localhost:8123/index.html
 
+      # play.html is the same game inlined into one file, for opening from a
+      # disk with no server. It is generated, so it can go stale, and it loads
+      # under file:// where fetch is refused — so it is rebuilt, compared, and
+      # then actually played from a file rather than trusted.
+      - name: Check the one-file build still matches web/
+        run: node web/build/standalone.mjs --check
+
+      - name: Play the one-file build straight off the disk
+        run: |
+          node web/test/browser.mjs --url "file://$PWD/play.html" --games 1
+          node web/test/input.mjs --url "file://$PWD/play.html"
+
   pipeline:
     # Proves the data -> train -> export -> serve path still works end to end,
     # on a dataset small enough to finish in a couple of minutes.

.gitignore

@@ -2,8 +2,9 @@ __pycache__/
 *.py[cod]
 .venv/
 venv/
-dist/
-build/
+/dist/
+# Anchored: setuptools writes ./build, but web/build holds source.
+/build/
 *.egg-info/
 .pytest_cache/
 .mypy_cache/

Makefile

@@ -1,5 +1,5 @@
 .PHONY: help setup test lint typecheck check train bench figures facts api ui play \
-        parity parity-check selfplay browser input capture web clean all
+        parity parity-check selfplay browser input capture standalone web clean all
 .DEFAULT_GOAL := help
 
 PY ?= python3
@@ -46,6 +46,10 @@ browser:  ## Load the page in Chrome and play a game (needs puppeteer-core)
 capture:  ## Re-record the screenshots and the clip in the README
 	$(NODE) web/test/capture.mjs --url http://localhost:$(PORT)/index.html
 
+standalone:  ## Rebuild play.html, the whole game in one openable file
+	$(NODE) web/build/standalone.mjs
+	$(NODE) web/test/browser.mjs --url file://$(CURDIR)/play.html --games 1
+
 web: parity selfplay  ## Every check that does not need a browser
 
 play:  ## Serve the game at http://localhost:$(PORT)

README.md

@@ -36,6 +36,13 @@ closed-form references.
 "Quick" playback the page offers, with the bot's search pauses capped at
 0.8 s. The shots are the game's, not an animation.*
 
+**Three ways in, none of which need a toolchain.** The link above, `make play`
+to serve `web/` yourself, or `play.html` — the whole game inlined into one file
+that plays when you open it from a disk, offline, with no server. Download it
+from the repository root and double-click it. `web/build/standalone.mjs` builds
+it, and CI plays a full game from `file://` on every push so the copy cannot
+quietly rot.
+
 No install, no build step, no framework — `web/` is plain ES modules, and the
 whole thing is served as static files. Aim with the mouse, drag back from the
 cue ball to strike, click the cue-ball diagram to move the tip off centre. Every