Release Cyd Bluesky archive v2 export after bidirectional compatibility passes

[micahflee]

Note

In this issue, “version 2” and “v2 archive” mean version 2 of the Cyd Bluesky archive contract. Cyd archive formats and version histories are platform-specific; this issue does not define version 2 for X, Facebook, Mastodon, or any other platform.

Parent

• Add full Bluesky platform support with mobile-compatible archives #672

What to build

Enable Desktop Cyd Bluesky archive v2 export only after released readers prove bidirectional semantics and supported-platform behavior.

Acceptance criteria

• A compatible Mobile Cyd Bluesky archive v2 reader is released before enablement.
• Tests pass Mobile→Desktop, Desktop→Mobile, repeated, and mixed independently collected round trips.
• The matrix covers every category, bounded context, all media/full video, incompleteness, deletion state, identity collisions, settings, and adversarial failures.
• Assertions compare normalized semantics, not ZIP bytes or SQLite layout.
• v1 and newer-version rejection remain clear.
• Save, import, Browse, export, and local-backup ownership remain free.
• The enabled workflow passes on macOS, Windows, and Linux with the documented diagnostic privacy boundary.

Blocked by

• Securely read and import a complete Cyd Bluesky archive v2 #680
• Preview and merge Cyd Bluesky archive v2 by Bluesky identity #681
• Resume Cyd Bluesky archive imports without partial account mutation #682
• Export recoverable Bluesky data with a release-disabled Cyd Bluesky archive v2 writer #683
• A released compatible Mobile Cyd Bluesky archive v2 reader

(This was written by an LLM.)