continuation: a reminder's day is written into its payload, not just its slot

Live check on the deployed daemon: "напомни сегодня о событиях" then "а
завтра?" fires tomorrow with the text still reading "сегодня". Re-aiming
Time is not enough when the day word is also inside the payload, and
rewriting the payload needs the date's span in the string, which
ParseCalendarDate does not report.

Reminder comes out of continuableIntents until that exists. query and
system are unaffected: their Time slot IS the whole question.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TrVSBKe3RFDF4fGYKWYQnX

cmd/mavend/continuation_test.go

@@ -67,8 +67,11 @@ func TestContinuationDeclinesWhatIsNotAnEllipsis(t *testing.T) {
 func TestContinuationDeclinesUncontinuableIntents(t *testing.T) {
 	// act is the one that matters: inheriting an allowlisted fn from a
 	// two-word utterance would be a way to run a destructive command.
+	// reminder is here because its payload is its Text, and the Text embeds
+	// the day word it was created with — see continuableIntents.
 	for _, in := range []dialogue.Intent{
-		dialogue.IntentAct, dialogue.IntentFact, dialogue.IntentNote, dialogue.IntentChat,
+		dialogue.IntentAct, dialogue.IntentFact, dialogue.IntentNote,
+		dialogue.IntentChat, dialogue.IntentReminder,
 	} {
 		if _, ok := continuationDecision(contSession(in, "water"), "а завтра?", contNow); ok {
 			t.Errorf("continuationDecision inherited intent %q, want refusal", in)