Bump golang.org/x/crypto to v0.52.0
Commit

Closes 13 open Dependabot alerts (7 critical, 3 high, 3 medium), all in the x/crypto SSH implementation. The dependency is pulled in transitively via go-git and ProtonMail openpgp; go-git still requires v0.51.0 and has no newer release, so we pin the indirect dependency directly via MVS.
Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Entire-Checkpoint: 01KX37KN6NXDTV10FKNCBPTP2Y
Checkpoints
Checkpoint 1