Add REST tests for explicitly-retired / non-active lifecycle records (not just superseded)

[dcfocus]

Summary

REST-layer lifecycle tests only cover the superseded branch of is_hidden_by_lifecycle. Add coverage for an explicitly retired record (and a non-active lifecycle_status) so all hiding branches are tested at the REST layer.

Background

is_hidden_by_lifecycle (crates/lance-context-core/src/record.rs) hides a record for three reasons:

1. superseded_by_id is set,
2. retired_at is set,
3. lifecycle_status is not active/contradicted.

The existing REST tests only exercise (1):

• search_respects_retired_visibility (crates/lance-context-server/src/routes/search.rs:257) — supersedes via update_record, then checks include_retired surfaces the original.
• list_respects_retired_visibility (crates/lance-context-server/src/routes/records.rs:881) — same supersession setup.

Branches (2) and (3) are untested at the REST layer, even though RecordPatchDto exposes retired_at / retired_reason / lifecycle_status (records.rs:425), so a client can put a record into those states over REST.

Proposed work

Add REST tests (mirroring the existing supersession tests) that:

• patch a record to set retired_at (without supersession) and assert it is hidden from default search / list, and surfaced when include_retired = true;
• patch a record to a non-active/contradicted lifecycle_status and assert the same default-hidden / include_retired-surfaced behavior.

Acceptance criteria

• New REST tests cover the retired_at and lifecycle_status hiding branches for both search and list.
• Tests assert default-hidden and include_retired = true-visible for each branch.

Notes

Small, self-contained test-coverage gap (flagged during the #89 / #92 REST filter work). good first issue.