voice/routing: fix time-query misroute (seed collision, threshold, stage-0 grammars)

three bugs causing time queries to land on reminder or fact intent:

- seed collision: query.txt and system.txt shared identical time/date
  seeds (который час, сколько времени), making system intent
  indistinguishable from query intent in centroid space
- threshold (0.35) too low for ONNX embedder — cosine similarities
  cluster 0.5-0.7 for related intents, so Clarify never fired
- reminder centroid contaminated by time-lexicon (every seed has a time
  expression), pulling any time-word utterance toward reminder intent

fixes:
- remove 3 duplicate time/date seeds from query.txt (keep in system.txt)
- DefaultRouterThreshold 0.35 -> 0.55
- stage-0 grammar for напомни/remind me -> IntentReminder, bypasses
  classifier (fixes 'напомни через час' being misrouted to fact)
- stage-0 grammars for time/date system queries (сколько времени,
  который час, какой сегодня день) -> IntentSystem, with Build filter
  to exclude elapsed/duration queries (сколько времени прошло)
- time parser fallback in applyAction for stage-0 reminder matches
  (extractor doesn't run on stage-0 decisions)

cmd/mavend/voice.go

@@ -229,6 +229,7 @@ func wireVoice(cfg *config.Config, coreAPI ipc.CoreAPI, phr phraser.Phraser, mem
 		memStore:         memStore,
 		dialogueSessions: dialogueSessions,
 		queryMinScore:    cfg.Voice.QueryMinScore,
+		timeParser:       router.StubDateTimeParser{},
 	}
 
 	// ----- the server (TCP listener) -----
@@ -268,6 +269,11 @@ type reactiveHandler struct {
 	// wireVoice from VoiceConfig; default 0.55.
 	queryMinScore float64
 
+	// timeParser — used as a fallback for stage-0 reminder grammar matches
+	// (where the extractor didn't run). Shared with the router's extractor.
+	// The production dateparser will replace StubDateTimeParser here too.
+	timeParser router.DateTimeParser
+
 	// dialogueSessions carries slots across turns for follow-ups (single-user
 	// box → one session slot, keyed voiceDialogueID). nil ⇒ no carry-over.
 	dialogueSessions *dialogue.SessionStore
@@ -443,7 +449,18 @@ func (h *reactiveHandler) applyAction(ctx context.Context, dec router.Decision)
 
 	case router.IntentReminder:
 		if !dec.Slots.HasTime {
-			return "не получилось разобрать время напоминания."
+			// Stage-0 (reminder-wakeword grammar) skips the extractor, so the
+			// time wasn't parsed. Run the parser as a fallback.
+			if dec.Stage == 0 && h.timeParser != nil {
+				t, ok, err := h.timeParser.Parse(ctx, dec.Utterance, h.now())
+				if err == nil && ok {
+					dec.Slots.Time = t
+					dec.Slots.HasTime = true
+				}
+			}
+			if !dec.Slots.HasTime {
+				return "не получилось разобрать время напоминания."
+			}
 		}
 		payload := `{"text":` + jsonString(dec.Utterance) + `}`
 		if _, err := h.api.CreateReminder(ctx, dec.Slots.Time, payload, ""); err != nil {
@@ -745,12 +762,15 @@ func (h *reactiveHandler) reply(ctx context.Context, text string, _ []string) (v
 //   - 6 bootstrap examples covering the 5 intents + one compound-capture
 //     placeholder. Spec calls for ~10 per intent at production; this is the
 //     bootstrapping floor swapped by tuning the seed set later.
-//   - Threshold is from voice.router_threshold config (default 0.35).
+//   - Threshold is from voice.router_threshold config (default 0.55).
 func buildRouter(emb router.Embedder, acts router.ActMatcher, threshold float64) *router.Router {
 	cls := router.NewClassifier(emb)
 	seedClassifier(cls)
+	grammars := router.DefaultGrammars(acts)
+	grammars = append(grammars, router.SystemTimeDateGrammars()...)
+	grammars = append(grammars, router.ReminderGrammar())
 	return router.New(router.Config{
-		Grammars:   router.DefaultGrammars(acts),
+		Grammars:   grammars,
 		Classifier: cls,
 		Extractor: router.Extractor{
 			Time:  router.StubDateTimeParser{},