crash: abort after releasing a detached node #1844

What happened

When a node stop in the background times out, ldk-node detaches the tasks it could not cancel. Releasing the node afterwards shuts its runtime down under them, and the app aborts natively on the next restart from the background (#1536).

Expected

When a stop leaves detached tasks, the app ends its process cleanly instead of releasing the node, so it never aborts. The ldk-node fix stays tracked in #1536.

See the PR that fixes it: #1838