agent (unreleased): fixes after an independent review — one lock for the writers of agent.json, the trust run serialised and bounded, the CA copy keeps its previous root, the profile stanza from the wrapper's answer, a stale give-up ends, both boot tokens from one read

Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

internal/osupdate/pvecacopy.go

@@ -26,7 +26,7 @@ type PVECACopyResult struct {
 // PVECACopy asks the wrapper to make or refresh the copy. An error names a refusal (T1–T3, or R11 from a wrapper that
 // does not know the mode yet) or a wrapper that gave no answer.
 func (l *Leg) PVECACopy(ctx context.Context) (PVECACopyResult, error) {
-	wr, err := l.call(ctx, "pveca"+l.now().UTC().Format("150405"), map[string]any{"release_id": "pve-ca-copy",
+	wr, err := l.call(ctx, "pveca"+l.now().UTC().Format("150405.000"), map[string]any{"release_id": "pve-ca-copy",
 		"layer": LayerHost, "mode": "pve-ca-copy"})
 	if err != nil {
 		return PVECACopyResult{}, err