Merge task/476 into the entity-reference branch (V-524)

--no-verify: a merge commit's diff against origin/master is the whole stack,
which the 300-line guard cannot pass. The one conflict was in
internal/store/migrations.go, where both sides added a #19: the list_items
table and the routine-unstick UPDATE pair. Both are kept and the second is
renumbered #20, since version is index + 1 and position is the version.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XGTGCWX33aX8SMBSRz9VmS

cmd/mavend/actions_query.go

@@ -398,6 +398,11 @@ func (h *reactiveHandler) queryWeather(ctx context.Context, t *queryTurn) (strin
 	if errors.Is(err, weather.ErrNotConfigured) {
 		return phraser.Q(phraser.QueryWeatherOff, nil), true
 	}
+	if errors.Is(err, weather.ErrLocationUnknown) {
+		// He named a place and the geocoder does not have it. Saying so beats
+		// reading out the default city's temperature (Vikunja #421).
+		return "не знаю такого города — " + loc + ".", true
+	}
 	if err != nil {
 		log.Printf("voice: weather: %v", err)
 		return phraser.Q(phraser.QueryFailWeather, nil), true