Distillation

🔴 (02:37) User stated the path-normalization logic strips a trailing path separator but never strips it from a bare filesystem root such as /.
🔴 (02:37) User stated upgrade-source resolution returns the successful probe response to the caller so the caller never repeats the successful network request.
🔴 (02:37) User stated package-manager installations always need network access to fetch and install packages; unlike direct binary upgrades, they cannot complete from cached version information alone and should produce an UpgradeError with code "unsupported_operation" when the required network operation is unavailable.
🔴 (02:37) User stated a legacy ~/.sentry/bin installation is the exception to preserving an existing direct-install directory: it should migrate to the XDG target returned by determineInstallDir after removing the legacy pin.
🔴 (02:37) User stated the upgraded binary’s setup process updates shell completions and agent skills and records installation metadata.
🔴 (02:37) User stated an interrupted binary download should surface guidance to rerun sentry cli upgrade.
🔴 (02:37) User stated SIGKILL on macOS can indicate that AMFI killed the upgraded binary.

Observations