f6781c107e
Commit 6aaabb5 added std/locks usage in vector/engine.nim (HNSW thread-safety).
std/locks requires --threads:on. Local builds worked because /etc/nim/nim.cfg
had threads:on, but GitHub Actions runners (setup-nim-action) compile without
threads by default, causing the test job to fail silently at runtime.
Also updated baradadb.nimble tasks for consistency.
Fixes GitHub Actions CI failure on test / clients-ci workflows.