Delete selected local Bluesky backup data safely

[micahflee]

Parent

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

What to build

A free user can reclaim storage through explicit local deletion without confusing it with source deletion or treating save settings as retention rules.

Acceptance criteria

• Selection by category/date previews record count, media count, and reclaimable size.
• The UI uses distinct local-deletion language and recommends exporting first.
• Only confirmed local records are removed; save-setting changes never trigger deletion.
• Media is collected only when that explicit deletion leaves it unreferenced.
• No other local account or Bluesky source is affected.
• A later Bluesky archive import can preview and restore deleted records.
• Real-storage controller tests verify boundaries, accounting, reference cleanup, isolation, and recovery; UI tests cover preview and confirmation.

Blocked by

• Save and browse public Bluesky records offline #676
• Save and browse Bluesky conversations offline #677
• Export recoverable Bluesky data with a release-disabled Cyd Bluesky archive v2 writer #683

(This was written by an LLM.)