[Advancement] Add install script checksum pinning and rollback instructions

[Nanle-code]

Objective

Harden install.sh with checksum pinning guidance and clear rollback instructions for failed upgrades.

Target area

install.sh, docs

Context

Curl-to-bash installs need stronger integrity UX for security-conscious users.

Requirements

• Document checksum verification flow
• Support version pinning
• Provide rollback steps if binary misbehaves

Acceptance criteria

• Docs demonstrate checksum verification
• Install script supports pinned version argument
• Rollback instructions tested manually and documented

Pull request merge requirements

Pull requests that resolve this issue must not be merged until all of the following are true:

1. All required CI checks are green on the latest commit of the PR (build, tests, lint/format, and any workflow jobs required by branch protection).
2. The branch has no merge conflicts with the target branch (master / default), and a clean merge or rebase is possible without unresolved conflicts.
3. Review feedback is addressed, and the change remains focused on this issue’s acceptance criteria.

Contributors should run the local CI-equivalent checks before opening or updating the PR (see CI_ENFORCEMENT.md and CONTRIBUTING.md).

[Michealshodipo56]

@Michealshodipo56 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I would like to work on this kindly assign me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Michealshodipo56 to this issue.

[Ahmedscreativeverse]

@Ahmedscreativeverse has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

i can resolve this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Ahmedscreativeverse to this issue.

[Sensei-Victor]

@Sensei-Victor has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Please assign this to me
It is ny dominant field

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Sensei-Victor to this issue.

[drips-wave]

Congratulations, @Sensei-Victor! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Sensei-Victor: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊