Preview and merge Cyd Bluesky archive v2 by Bluesky identity

[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

A user can preview category, identity, restoration, and settings effects before idempotently merging Cyd Bluesky archive v2 data into a new or existing local account.

Acceptance criteria

• DID matching preserves an existing UUID; a new DID adopts an unused Cyd Bluesky archive UUID; unrelated UUID collisions are remapped and reported.
• Records merge by stable identifiers, retain absent local data, prefer newer observations, and preserve populated fields.
• Assets collapse by digest and repeat import has no additional effect.
• Category selection defaults to all and automatically includes required context/media.
• The preview reports data restored after local deletion and allows that recovery.
• New accounts receive portable defaults; existing settings change only by explicit adoption.
• Credentials, schedules, jobs, logs, caches, diagnostics, and UI state never import.
• Fixture tests cover identity collisions, handles, union/repeat merges, observations, selection, restoration, and settings.

Blocked by

• Securely read and import a complete Cyd Bluesky archive v2 #680

(This was written by an LLM.)