Merged 10 upstream commits (MemTable, read-your-writes tests, feed endpoint,
security hardening, signed assertions, source registry, dashboard enhancements)
and fixed all test failures across the full workspace (2656/2656 passing).
Key fixes:
- fix(cluster): DashMap deadlock in swim.rs suspect_node/fail_node/alive_node
- DashMap::get_mut RefMut + iter() on same map = non-reentrant write lock deadlock
- Fix: extract clone in scoped block to drop RefMut before calling update_node_gauges()
- 6 previously-hanging SWIM tests now pass in <2s
- fix(sim): replace background-task+polling ingestion with synchronous process_pending()
- smoke_high_volume_simulation was CPU-starved under 2656 parallel tests
- Removed ingestor.start() + wait_until_ingested() pattern throughout sim
- All arena functions now call ingestor.process_pending() directly (deterministic)
- fix(test): v2 signature helper used wrong hash (rkyv vs canonical compute_content_hash_v2)
- fix(test): quota test signed "test" but v1 requires "subject:predicate" format
- fix(test): http_validation now accepts 400 for valid-format-but-invalid-crypto hex
- fix(test): scale_adaptive micro tier assertions updated (auto_promote upstream change)
- config: add nextest.toml with slow-timeout for background-task-tests group
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
