scoreboard: 147/300 (49.0%) wide, up from 114/300 baseline

Math 40% / Number 73% / String 33% = 147/300 (49.0%), +33 tests since
session-3 start. Wall time 277s (vs prior 593s baseline → 2.14× via
harness cache).

Top remaining failure modes (141 fails, 12 timeouts):
- 115× Test262Error (assertion failed) — numeric precision at
  MAX_VALUE/MIN_VALUE boundary, (new Number()).constructor chain,
  toFixed edge cases, String.fromCharCode code-point ranges
- 34× TypeError: not a function — still the missing Math trig
  primitives (filed as Blocker)
- 12× Timeout — long-running String loops

lib/js/test262-scoreboard.json

@@ -1,12 +1,12 @@
 {
   "totals": {
-    "pass": 115,
-    "fail": 174,
+    "pass": 147,
+    "fail": 141,
     "skip": 1597,
-    "timeout": 11,
+    "timeout": 12,
     "total": 1897,
     "runnable": 300,
-    "pass_rate": 38.3
+    "pass_rate": 49.0
   },
   "categories": [
     {
@@ -35,15 +35,15 @@
     {
       "category": "built-ins/Number",
       "total": 340,
-      "pass": 44,
-      "fail": 52,
+      "pass": 74,
+      "fail": 22,
       "skip": 240,
       "timeout": 4,
-      "pass_rate": 44.0,
+      "pass_rate": 74.0,
       "top_failures": [
         [
           "Test262Error (assertion failed)",
-          52
+          22
         ],
         [
           "Timeout",
@@ -54,30 +54,30 @@
     {
       "category": "built-ins/String",
       "total": 1223,
-      "pass": 31,
-      "fail": 63,
+      "pass": 33,
+      "fail": 60,
       "skip": 1123,
-      "timeout": 6,
-      "pass_rate": 31.0,
+      "timeout": 7,
+      "pass_rate": 33.0,
       "top_failures": [
         [
           "Test262Error (assertion failed)",
-          53
+          50
         ],
         [
           "Timeout",
-          6
+          7
         ],
         [
           "ReferenceError (undefined symbol)",
           2
         ],
         [
-          "Unhandled: Not callable: \\\\\\",
+          "Unhandled: Not callable: {:__proto__ {:toLowerCase <lambda(&rest, args)",
           2
         ],
         [
-          "Unhandled: Not callable: {:__proto__ {}} (kont=6 frames)\\",
+          "Unhandled: Not callable: \\\\\\",
           2
         ]
       ]
@@ -96,42 +96,38 @@
   "top_failure_modes": [
     [
       "Test262Error (assertion failed)",
-      128
+      95
     ],
     [
       "TypeError: not a function",
-      37
+      38
     ],
     [
       "Timeout",
-      11
+      12
     ],
     [
       "ReferenceError (undefined symbol)",
       2
     ],
+    [
+      "Unhandled: Not callable: {:__proto__ {:toLowerCase <lambda(&rest, args)",
+      2
+    ],
     [
       "Unhandled: Not callable: \\\\\\",
       2
     ],
-    [
-      "Unhandled: Not callable: {:__proto__ {}} (kont=6 frames)\\",
-      2
-    ],
     [
       "SyntaxError (parse/unsupported syntax)",
       1
     ],
     [
-      "Unhandled: Not callable: {:__proto__ {}} (kont=5 frames)\\",
-      1
-    ],
-    [
-      "Unhandled: js-transpile-binop: unsupported op: >>>\\",
+      "Unhandled: Not callable: {:__proto__ {:valueOf <lambda()> :propertyIsEn",
       1
     ]
   ],
   "pinned_commit": "d5e73fc8d2c663554fb72e2380a8c2bc1a318a33",
-  "elapsed_seconds": 288.0,
+  "elapsed_seconds": 277.0,
   "workers": 1
 }