Bug fixes:
- Preserve existing tags when re-adding a duplicate card
- Include unreviewed cards in difficulty/stability filters
- Show Default deck in import response deck list
- Use interface-agnostic language in force-overwrite error
- Add --no-buried flag to match --no-suspended pattern

README rewritten to lead with agent conversation transcript
and MCP setup, reflecting the primary use case.

Bump version to 0.3.0.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>