Users have no canonical way to upgrade sandnote from the CLI

[laotoutou]

Summary

sandnote currently documents installation paths, but it does not provide a canonical CLI command for upgrading an existing installation.

Problem

A user asked whether sandnote has an upgrade command. The current answer is no:

• the root CLI command set does not include upgrade
• the README documents install flows, but not a standard upgrade flow

That means users have to guess how they should update an existing sandnote binary.

Expected behavior

Users should have one clear, documented way to upgrade sandnote, ideally through a canonical command or an equally clear supported workflow.

Why it matters

• reduces ambiguity for end users
• makes automation and agent guidance more reliable
• avoids inconsistent upgrade instructions across install methods
• improves the overall CLI contract

Current evidence

• internal/cli/root.go registers init, index, version, overview, resume, artifact, entry, thread, workspace, topic, and repl, but not upgrade
• README.md documents installation methods such as curl | bash, PowerShell, and go install, but does not define a canonical upgrade command

Possible directions

• add sandnote upgrade
• or explicitly document that upgrade is done by re-running the installer / go install
• or support both, but define one canonical recommendation