erlang: erlang:send_after/3 + cancel_timer/1 + monotonic_time (T1+T2, 766/766)

Logical-clock timer wheel in the scheduler. send_after schedules a
message-delivery event at an absolute deadline (clock + Time ms);
cancel_timer marks a live timer cancelled and reports remaining ms,
or false. Time advances only when the runnable queue drains, jumping
to the earliest pending deadline (deterministic, no wall clock).

monotonic_time/0,1 exposes the logical ms clock.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/erlang/scoreboard.json

@@ -1,7 +1,7 @@
 {
   "language": "erlang",
-  "total_pass": 761,
-  "total": 761,
+  "total_pass": 766,
+  "total": 766,
   "suites": [
     {"name":"tokenize","pass":62,"total":62,"status":"ok"},
     {"name":"parse","pass":52,"total":52,"status":"ok"},
@@ -13,6 +13,7 @@
     {"name":"echo","pass":7,"total":7,"status":"ok"},
     {"name":"fib","pass":8,"total":8,"status":"ok"},
     {"name":"ffi","pass":37,"total":37,"status":"ok"},
-    {"name":"vm","pass":78,"total":78,"status":"ok"}
+    {"name":"vm","pass":78,"total":78,"status":"ok"},
+    {"name":"send_after","pass":5,"total":5,"status":"ok"}
   ]
 }