feat(course): audit fixes and twelve extensions (Modules 7b, 12, 13)

Audit pass:
- Frame rule counts frames since the last move, so every step lasts
  exactly movesEvery(score) frames, also right after a speed-up
- clampTime + MAX_GAP_MS: a hidden tab no longer replays the whole gap
- Pong Restart keeps held keys
- Fact corrections (mulberry32 output coverage, Haskell IO, uniform)
- New fixture cases from a mutation analysis

Extensions (all three tracks, shared fixtures, course text):
- Turn queue (Exercise 10.6), persisted high score (10.7),
  replay viewer (10.8), play() end-to-end helper (9.5)
- Optional State (4.7) and optional Module 7b, stack-safe IO
- Module 12, property-based testing with generators, shrinking,
  invariants and a model-based oracle
- Module 13, Conway's Life with a Click event
- JS type checking via jsconfig, JSDoc and types.d.ts
- Maintainer tools: scripts/mutate.mjs, scripts/typecheck-js.sh,
  Playwright end-to-end suite (e2e/, scripts/e2e.sh)

Docs: docs/contract.md is the canonical contract; specs and build log
under docs/superpowers.

Verified: JS 728, Scala 689, F# 691 unit tests; stubs and progression
M01-M13 and M07b; 176 end-to-end tests on Chromium and WebKit.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

fixtures/m05-update.json

@@ -22,7 +22,8 @@
           "seed": 0,
           "score": 0,
           "status": "Playing",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Tick"
@@ -46,7 +47,8 @@
         "seed": 0,
         "score": 0,
         "status": "Playing",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -70,7 +72,8 @@
           "seed": 0,
           "score": 0,
           "status": "Playing",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Tick"
@@ -98,7 +101,8 @@
         "seed": 1831565813,
         "score": 1,
         "status": "Playing",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -122,7 +126,8 @@
           "seed": 0,
           "score": 0,
           "status": "Playing",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Tick"
@@ -146,7 +151,8 @@
         "seed": 0,
         "score": 0,
         "status": "GameOver",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -170,7 +176,8 @@
           "seed": 0,
           "score": 0,
           "status": "Paused",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Tick"
@@ -194,7 +201,8 @@
         "seed": 0,
         "score": 0,
         "status": "Paused",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -218,7 +226,8 @@
           "seed": 0,
           "score": 0,
           "status": "Playing",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Turn",
@@ -243,7 +252,8 @@
         "seed": 0,
         "score": 0,
         "status": "Playing",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -267,7 +277,8 @@
           "seed": 0,
           "score": 0,
           "status": "Playing",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Turn",
@@ -292,7 +303,8 @@
         "seed": 0,
         "score": 0,
         "status": "Playing",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     },
     {
@@ -316,7 +328,8 @@
           "seed": 0,
           "score": 0,
           "status": "Paused",
-          "frame": 0
+          "frame": 0,
+          "queued": null
         },
         {
           "tag": "Turn",
@@ -341,7 +354,8 @@
         "seed": 0,
         "score": 0,
         "status": "Paused",
-        "frame": 0
+        "frame": 0,
+        "queued": null
       }
     }
   ]