perry-stdlib lib tests fail on clean main (macOS): fetch::lifecycle GC tests, randomBytes callback, async_bridge roots; aborts even single-threaded #11417

The perry-stdlib library unit tests (cargo test -p perry-stdlib, lib target) fail every time on macOS aarch64 on clean main (a15b224..current, 2026-09-26). The same failure set shows up on #11402's branch, so that PR doesn't cause it.

Evidence. The debug lib test binary was run directly, 6 times per arm (main, and #11402 rebased on main):

• main: 6/6 runs failed, and only 2/6 reached a result line (172 passed; 9 failed, 174 passed; 7 failed). The others aborted.
• RUST_TEST_THREADS=1 on main: still fails. One run stopped at streams::pipe::tests::pipe_keeps_locks_until_async_abort_settles; another aborted with "thread caused non-unwinding panic".

Failing tests (counts over 7 runs that produced results):

• 7x fetch::lifecycle::root_shape_tests::minor_keeps_registry_edges_and_thread_exit_releases_entries
• 7x fetch::lifecycle::moving_collection_rewrites_live_method_cache_before_full_reclamation
• 7x fetch::lifecycle::lifecycle_tests::readers_survive_a_full_trace_that_releases_ids_of_their_own_kind
• 7x fetch::lifecycle::lifecycle_tests::a_young_id_and_its_edges_survive_the_first_full_trace
• 7x crypto::random::tests::native_dispatch_random_bytes_value_form_fires_callback (randomBytes callback must fire)
• 6x fetch::lifecycle::root_shape_tests::heap_container_and_raw_native_slot_keep_handles_alive
• 4x fetch::lifecycle::tests::full_collection_reclaims_fetch_handles_and_retains_edges
• 4x fetch::lifecycle::ownership_tests::request_signal_and_form_data_files_follow_their_owners
• 2x common::async_bridge::tests::async_bridge_pending_resolution_scanner_emits_promise_and_result_roots
• plus the young-log rule-1 debug assertion (gc/young_log.rs:173, perry-stdlib lib tests: GC young-log rule-1 assertion fires in readline listeners_provider test on main #11319) aborting whole runs.

Whether CI runs this lib suite on every PR is worth checking: ci_plan.py scopes cargo-test. If it doesn't, the suite has been red without a gate noticing.