Circuit-breaker pause for stealth-sender and wraith-names

[truthixify]

Extra labels: security, feature
Tier: L (5-7 days) | Type: feature + security

Context. Only stealth-announcer has a pause guard today. If a live vuln is disclosed against stealth-sender or wraith-names, the only mitigation is a full upgrade (hours, multi-sig). Withdrawals must remain enabled while paused so users can always exit.

Scope.

• Add Paused storage + pause / unpause / is_paused gated by Admin.
• Guard every state-mutating entrypoint EXCEPT withdrawal / reveal / lookup with require_not_paused().
• Emit Paused / Unpaused events matching the topic pattern in stealth-announcer.
• Extend PAUSE.md + MULTISIG.md.

Acceptance.

• cargo test --workspace covers pause / unpause / paused-call rejection for both contracts
• Withdrawal on stealth-sender and reveal / lookup on wraith-names remain callable while paused (dedicated tests)
• SAC Smoke and Futurenet Integration still green
• PAUSE.md updated with the guarded surface per contract

Files. stealth-announcer/src/pause.rs (reference), stealth-sender/src/lib.rs, wraith-names/src/lib.rs, PAUSE.md, EVENT_TOPIC_DESIGN.md.

[Meet-hybrid]

@Meet-hybrid has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Please can I work on this please?

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

[drips-wave]

Congratulations, @Meet-hybrid! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

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