Replace the fragile `latestRelayListEventIdHex` UserDefaults lookup in
`getLatestNIP65RelayListEvent()` with a direct nostrdb query using
`ndb.query(filters:maxResults:)` on the AUTHOR_KINDS index. This
eliminates the stale-hex failure mode where relay add/remove operations
would silently fall back to bootstrap or year-old relay lists.
Add an in-memory `lastSetRelayList` cache to bridge the nostrdb async
write gap — `set()` populates it, `getUserCurrentRelayList()` checks it
first, and `load()` clears it once ndb has committed.
Remove `latestRelayListEventIdHex` from: Delegate protocol,
DamusState, SaveKeysView, UserSettingsStore, and all test mocks.
Includes 5 regression tests that fail before the fix and pass after:
- testRemoveRelayDoesNotFallBackToBootstrapList
- testCacheBridgesAsyncWriteGap
- testRapidSequentialRemovesDoNotReintroduceRelays
- testLoadClearsCacheAndReadsFromNdb
- testNdbQueryFindsRelayListWithoutStoredHex
Changelog-Fixed: Fix stale relay list causing inability to disconnect relays
Closes: #3537
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: alltheseas <alltheseas@users.noreply.github.com>
