* Fix nightly SSH remote daemon checksum mismatch
Each nightly build overwrites the shared cmuxd-remote-* assets on the
nightly release, but older nightly DMGs have manifests with checksums
from their build time. When a user's nightly is even one build behind,
the downloaded binary doesn't match their embedded manifest.
Two-layer fix:
1. CI: version nightly remote daemon asset names with the build number
(e.g. cmuxd-remote-darwin-arm64-2362248028801) so each nightly's
manifest points to immutable files. Unsuffixed "latest" copies are
still uploaded for tooling compatibility.
2. Client: on checksum mismatch, fetch the live manifest from the
release and verify against that. This handles users on older
nightlies that predate the CI fix.
Fixes https://github.com/manaflow-ai/cmux/issues/1745
* Fix unsuffixed checksums file to use generic filenames
Regenerate cmuxd-remote-checksums.txt from the unsuffixed alias
binaries so `shasum -c` works against the generic asset names.
Also document that unsuffixed manifest intentionally keeps versioned
downloadURLs and that aliases don't carry attestation.
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Co-authored-by: Lawrence Chen <lawrencecchen@users.noreply.github.com>
