Import bookmarks and browsing history from other browsers

Summary

Let users migrate bookmarks and browsing history from supported browsers into Photon.

Scope

• Discover and import supported local browser profiles with clear source selection.
• Let users choose data categories and preview counts before applying an import.
• Validate URLs and titles, deduplicate predictably, and preserve existing Photon data if an import fails.
• Start with bookmarks and browsing history; treat credentials and cookies as a separate security and compatibility decision.
• Keep parsing and file access in Rust storage/import code, with progress shown in the native UI.

Acceptance criteria

• The user can review the source and selected categories before any profile data changes.
• Re-running an import does not silently create duplicate bookmarks or history rows.
• Unsupported, locked, or malformed source data produces a useful error and leaves Photon data intact.

Design reference: Zephium’s onboarding imports browser data into explicit destination categories: https://github.com/zephium-browser/Zephium