mavend, router: stop three sources claiming turns the world should answer (V-474)

The querySources order predates the 2026-08-02 ruling that live search leads.

An unconfigured feeds source claimed every news question and answered with a
configuration status, so "что происходит сейчас в новостях про искусственный
интеллект?" never reached the search sitting one source below. It now claims
only when neither SearXNG nor the ZIMs are configured, which is the case the
"не читаю ленты" line was written for — general knowledge would otherwise
invent a bulletin.

The calendar matches on a day word alone and sits above the weather, so
"какая сегодня погода в Москве?" answered "на 02.08.2026 ничего нет." It now
steps aside on weather wording, the same bail-out queryHome already does.

"что нового в лентах?" routed system and answered "пока не умею", while the
same question worded with "новостях" worked. FeedQueryGrammar routes it to
query at stage 0, requiring an ask word and a feed noun so the bare greeting
"что нового?" stays a greeting. Wired in the eval too, since the fixture is
only worth anything while its grammar set is the daemon's.

Also: the claiming source is now logged. /trace is the nudge-rule trace and
carries no query-source field, so a wrong answer could not be told apart from
a wrongly-ordered chain.

Kiwix having no live coverage is filed separately as V-508 — it is a decision
about search quality, not an ordering fix.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cmd/mavend/feeds_test.go

@@ -194,3 +194,22 @@ func TestFeedWorkerFetcherIsAllowlisted(t *testing.T) {
 		t.Fatal("the poller fetched a private address")
 	}
 }
+
+// TestQueryFeedsPassesWhenTheWorldCanAnswer — the defect (Vikunja #474). The
+// deployed box has no feeds block and does have SearXNG, and "что происходит
+// сейчас в новостях про искусственный интеллект?" got a configuration status
+// instead of the live answer sitting one source below.
+func TestQueryFeedsPassesWhenTheWorldCanAnswer(t *testing.T) {
+	h := buildFeedHandler(t, false)
+	h.search = &searchWiring{max: 3, runes: 1500}
+
+	if reply, ok := askFeeds(t, h, "что нового в лентах?"); ok {
+		t.Fatalf("feeds off with a search configured must fall through, got %q", reply)
+	}
+	// With nothing below that reads the world, the honest status is still said:
+	// general knowledge would otherwise answer with an invented bulletin.
+	h.search = nil
+	if reply, ok := askFeeds(t, h, "что нового в лентах?"); !ok || !strings.Contains(reply, "не настроены") {
+		t.Fatalf("no search and no ZIMs: reply = %q, ok = %v", reply, ok)
+	}
+}