chore: baseline snapshot before moderation-strictness feature

Repo .git was damaged (refs/ missing, index truncated, object store near-empty).
Repaired via git init (rebuilt refs), stale index preserved as .git/index.corrupt-20260910.bak,
then full worktree committed as a rollback baseline.

internal/dbutil/clock.go

@@ -0,0 +1,11 @@
+// Copyright 2021 E99p1ant. All rights reserved.
+
+package dbutil
+
+import (
+	"time"
+)
+
+func Now() time.Time {
+	return time.Now().Truncate(time.Microsecond)
+}