[Advancement] Add end-to-end privacy mode that disables network side channels

[Nanle-code]

Objective

Provide a strict privacy mode that disables telemetry, marketplace auto-updates, and AI cloud calls.

Target area

privacy/telemetry/config

Context

Users in sensitive environments need a single switch for network side channels.

Requirements

• One config/env switch enables strict privacy
• Commands needing network fail with explicit reason when blocked
• Document what remains local-only

Acceptance criteria

• Strict mode blocks enumerated side channels in tests
• Docs enumerate disabled features
• Default remains unchanged for existing users

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).

[itzkingaddie]

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

I can provide a good PR

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