You'll notice
The native updater verifies a signed release manifest before trusting checksums and installing a new binary.
The native binary updater now fetches a manifest.json.raw-sig.json sidecar and verifies an RSASSA-PKCS1-v1_5-SHA512 signature over the manifest against a pinned public key before trusting the checksums and platform info used to download and install a new Claude Code binary. Releases that predate signing can still be accepted in some modes, and enforcement of the check is itself controlled remotely.