Add util.EraseFile, which overwrites a file with zeros, syncs it, and removes it. loadParticipationKeys uses it for the key files it imports, and InstallParticipationKey for its temporary copy of an uploaded key. A symbolic link, or a file with other hard links, is only removed, so a copy the operator keeps elsewhere is not destroyed. As with secure_delete, copy-on-write file systems, snapshots and flash translation layers may keep the old blocks.

Removes the in-repo Pera adapter (@txnlab/use-wallet-pera) now that Pera
publishes and maintains it as @perawallet/use-wallet-pera. Examples, docs
and the README now install and import the npm package.

The thread was started without a wn.wg.Add(1) and blocked on
messagesOfInterestRefresh with no exit path, so it outlived Stop() for
the life of the process. Register it on the WaitGroup and let it return
when the network context is cancelled.

Found by the Go goroutine leak profile (Go 1.26 experiment, default in
1.27), which reported 43 of these blocked forever at the end of the node
package's test binary.

The new test fills messagesOfInterestRefresh after Stop and checks that
nothing drains it; it fails without the fix.

Commented out npm publish and GitHub release steps.

Docs/nodely deployment guide

Moved permissions section under the publish job.

Updated GitHub Actions to use newer versions of checkout and setup-node.

docs: address review nits on Accounts page