better sqlitestore prewarming

internal/oplog/sqlitestore/prewarm.go

@@ -0,0 +1,16 @@
+package sqlitestore
+
+import (
+	"github.com/ncruces/go-sqlite3"
+	_ "github.com/ncruces/go-sqlite3/embed"
+)
+
+// init kicks off wazero's compilation of the embedded SQLite WASM binary in
+// the background. The compile is guarded by a sync.Once inside go-sqlite3, so
+// any later sql.Open call simply waits on the same Once if it isn't done yet.
+// The goal is to move this multi-second cost off the critical path of the
+// first sqlite open, which otherwise inflates startup latency and burns into
+// per-test deadlines (notably under -race).
+func init() {
+	go sqlite3.Initialize()
+}