Phase-1 → Signal migration path

[codebestia]

Define how existing Phase-1 sealed-box conversations transition to Signal without losing history: keep decrypting old envelopes with the sealed-box path; encrypt all new messages via Signal once both devices support it (capability flag on user_devices). Document the cutover.

Acceptance criteria:

• Old messages still decrypt; new ones use Signal when both sides capable
• Capability negotiation via a device flag
• No history loss across the cutover

[muizbolaji4]

@muizbolaji4 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello maintainer, This issue matches my experience, and I'd appreciate the opportunity to work on it.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @muizbolaji4 to this issue.

[Martins-594]

@Martins-594 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello, I'm requesting assignment for this issue and will make sure the implementation meets your standards.

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[Olorunfemi20]

@Olorunfemi20 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello! This issue aligns well with my experience, and I'd like to work on it. I've already reviewed the expected behavior and have a good understanding of the implementation required. I'm confident I can deliver a polished solution that meets the project's standards.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Olorunfemi20 to this issue.

[privyy-bit]

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

i would like to work on this issue kindly assign me

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

[drips-wave]

Congratulations, @Olorunfemi20! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @Olorunfemi20: 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.

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