[Flaky test]: workflow launch replay can race durable surface owner lease release under parallel Linux tests

[echoVic]

Environment

• Orca: 0.4.32
• Source: 66a68035c6ee5851fa519aae1c6a131c9699f2ac
• Host: Linux x86_64
• Rust: 1.98.1
• Runner: cargo nextest, profile ci, framework retries disabled

Summary

The following test can fail during a parallel workspace run because workflow replay attempts to acquire the typed surface owner lease before the previous owner has been observably released:

orca-runtime::runtime_surface_host
workflow_launch_replay_uses_surface_identity_when_activation_store_is_missing

Failure

During the parallel run:

take over workflow thread: ThreadStartFailed {
    message: "failed to acquire typed surface owner lease: AlreadyOwned"
}

Location:

crates/orca-runtime/tests/runtime_surface_host.rs:1692

Reproduction evidence

A workspace run excluding the sandbox-dependent suites executed 3169 tests:

3168 passed
1 failed

The only failing test was:

workflow_launch_replay_uses_surface_identity_when_activation_store_is_missing

The same test was then run independently and serially three times:

for i in 1 2 3; do
  cargo test \
    -p orca-runtime \
    --test runtime_surface_host \
    workflow_launch_replay_uses_surface_identity_when_activation_store_is_missing \
    --locked \
    -- \
    --nocapture \
    --test-threads=1
done

Result:

3/3 passed

This points to a parallel scheduling/lifecycle race rather than a deterministic functional failure.

Expected behavior

Once the first runtime owner has been shut down or relinquished, replay should wait for or observe the committed lease-release boundary before attempting takeover.

The test should not depend on scheduler timing or filesystem visibility.

Suggested fix

• Introduce an observable synchronization boundary proving that the previous owner lease has been released before takeover begins.
• If lease release is durable, wait for the committed revision or ownership transition rather than process/thread completion alone.
• Ensure all owner exit paths release or fence the lease symmetrically.
• Add a parallel stress regression that repeatedly exercises:
  1. initial owner acquisition;
  2. activation-store removal;
  3. owner shutdown/release;
  4. replay takeover.

Please avoid fixing this with a larger sleep, blind retry, or relaxed assertion; those would only lower the failure probability.