docs(course): consistency pass

- m04: F# mulberry32 hints and skeleton route * and + through uint64 helpers;
  new 'F# in the browser' note on the Fable uint32 trap
- m01-m05: 'About test names' notes like m06-m11; m00 explains JS vs Scala/F# titles
- m00/m09: first build-web.sh run restores Fable; m09 JS file list (main.js is given)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

course/05-folding-time.md

@@ -166,6 +166,8 @@ The game loop from the top of this module becomes: **the states of the game are
 
 ## Exercises
 
+> **About test names.** The test titles quoted under "Tests" are the JavaScript ones; the JS runner prints them with the module in front (`m05 history has one more state than there are actions`). The Scala and F# suites use the same titles. Failing tests are reported by name when you run the module's tests; to read all titles, open `scala/test/M05Game.test.scala` or `fsharp/tests/M05Game.fs`. Fixture-based tests have the same case names in every track (JS `m05 replay: twelve-actions-eat-one-apple`, Scala/F# `replay: twelve-actions-eat-one-apple`).
+
 ### Exercise 5.1 — `update`
 
 `Tick` runs a game step (`tick` from `spawn`), `Turn(dir)` asks to turn (`turn` from `rules`), every other action returns the state unchanged.