Route GORM's logger through slog and bound it (closes #178)

internal/gormlog/export_test.go

@@ -0,0 +1,17 @@
+package gormlog
+
+import (
+	"log/slog"
+	"time"
+)
+
+// ExportNewWithSlowThreshold builds a Logger whose slow-statement
+// threshold is d rather than DefaultSlowThreshold, so a test can pin
+// which arm of Trace it is exercising instead of racing the clock on a
+// loaded machine. The threshold is set at construction, like every
+// other field, so the type's concurrency guarantee still holds.
+func ExportNewWithSlowThreshold(
+	log *slog.Logger, d time.Duration,
+) *Logger {
+	return &Logger{log: log, slowThreshold: d}
+}