When importing from 1Password (.1pif or .1PUX files), Proton Pass ignores createdAt and updatedAt timestamps present in the source JSON payload. The importer uses the current date instead, losing valuable historical data.

Current Behavior:
- Imported items receive new created/modified dates based on import timestamp
- Original 1Password metadata (createdAt, updatedAt Unix timestamps) is silently dropped
- No warning or option to preserve these fields

Proposed Solution:
During import, detect and offer to preserve ignored metadata fields:

1. Scan payloads for unused fields (e.g., createdAt, updatedAt)
2. Report count of affected entries (e.g., "Found 616 items with createdAt field")
3. Allow users to map each field to a custom field type (Date or Text)
4. Populate the mapped fields across all affected entries

Why This Matters:
- Audit trail: See when credentials were originally created or last modified
- Migration transparency: Track what changed during transition
- Compliance: Many organizations need historical modification records

Implementation Effort:
This is a low-effort, high-value change. The data exists in the export — it just needs to be routed to Proton Pass custom fields during import.

Workaround Attempted:
Manually editing the Proton Pass JSON export is risky and complex. Better to build this into the import tool.