Deats,
- `test_echoserver_detailed_mechanics`: add `is_forking_spawner`
param, wrap `main()` in `fa_main()` with per-backend
`trio.fail_after` (4s fork / 1s trio) to cap cancel-cascade
teardown that compounds under forkserver.
- `test_sigint_closes_lifetime_stack`: swap `start_method` param
for `is_forking_spawner`, pre-init `tmp_file`/`ctx` to `None` so
KBI firing before `open_context` body doesn't `UnboundLocalError`,
add `pytest.fail` guard for the spawn-time IPC race case, arm
`signal.alarm` AFK-safety cap (10s) under fork backends
Also,
- `pytestmark`: add `track_orphaned_uds_per_test` +
`detect_runaway_subactors_per_test` fixtures.
- `delay()`: hardcode `return 1e3` at top (debug override still in
place).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 7ee0dc2e8f)