feat(api-keys): return real last_used in list + render in settings (rant 2026-08-24T12:41:25)

[argszero]

Summary

Settings page API Key "最近使用" (last used) column now shows real data instead of a hardcoded "从未" placeholder (rant 2026-08-24T12:41:25).

Findings: the api_keys.last_used column already existed and the gateway Bearer auth extractor already calls touch_api_key on every authenticated request (src/routes/mod.rs), so the column was being maintained — the gaps were:

1. list_api_keys (src/dao.rs) didn't SELECT last_used, so the API never returned it
2. Frontend renderSettings hardcoded last: T("settings.ak.last.never"), discarding any real value

Changes:

• Backenddao::list_api_keys: SELECT last_used and return it in the JSON (null for never-used keys, UTC ISO string otherwise, converted via utc_iso)
• FrontendrenderSettings: use k.last_used — real keys show the actual time (relative display + precise absolute time in the hover tooltip via timeCell); keys with null last_used show the "从未" placeholder
• Test: extended api_keys_create_and_list_with_bearer — asserts the last_used field is present, is null for a freshly created unused key, and is a non-empty string when populated

Cache-bust 20260824-7 → 20260824-8.

Tests

• cargo test 146/146 (incl. new last_used assertions), cargo fmt --check, cargo clippy green
• node --check OK