fix: realm 编号加 512 上界断言并降 kernel 重建缺省防符号键碰撞

crates/oxide_test262/src/config.rs

@@ -95,7 +95,7 @@ impl RunConfig {
           \x20  OXIDE_TEST262_CHUNK_SIZE             tests per child in chunked mode\n\
           \x20  OXIDE_TEST262_CHILD_CHUNK            marks a spawned child as chunk worker (any value)\n\
           \x20  OXIDE_TEST262_ALLOW_FAIL_EXIT        child may exit 1 on fail (any value)\n\
-          \x20  OXIDE_TEST262_KERNEL_BATCH           kernel rebuilds every N tests (default 5000, 1000 under --no-skip)\n\
+          \x20  OXIDE_TEST262_KERNEL_BATCH           kernel rebuilds every N tests (default 256, kept under the 512 realm bound)\n\
           \x20  OXIDE_TEST262_LOG_LEVEL              runner log level (default info)\n\
           \x20  OXIDE_SKIP_UNTIL                      skip test indexes below N (chunking/supervise resume)\n\
           \x20  OXIDE_MAX_TESTS                       run at most N tests after skip point"

crates/oxide_test262/src/main.rs

@@ -173,11 +173,13 @@ fn run_tests() -> bool {
         .and_then(|n| skip_until.checked_add(n))
         .map(|n| n.min(total))
         .unwrap_or(total);
+    // 缺省 256：每 kernel 生命周期 realm 计数不超 512 上界（属性键符号空间约束），
+    // 留一倍余量防重建边界 off-by-one 触发 debug 断言。
     let kernel_batch = std::env::var("OXIDE_TEST262_KERNEL_BATCH")
         .ok()
         .and_then(|s| s.parse::<usize>().ok())
         .filter(|&n| n > 0)
-        .unwrap_or(if config.no_skip { 1000 } else { 5000 });
+        .unwrap_or(256);
     let chunk_size = std::env::var("OXIDE_TEST262_CHUNK_SIZE")
         .ok()
         .and_then(|s| s.parse::<usize>().ok())