feat(offer): sort and align the §4.4 price tables, style them for both themes

- packs sorted by ascending rouble price;
- values grouped hints-only -> no-ads-only -> no-ads+hints -> tournament
  (the tournament group is empty until such products become sellable),
  ascending chip price within each group;
- price columns right-aligned (GFM "---:" separators);
- tables span the full content width; the name column shrinks to its content
  and never wraps;
- muted-but-visible cell borders on the dark theme, where the section rule
  colour blends into the background.

backend/internal/payments/offer_test.go

@@ -31,8 +31,10 @@ func TestProjectOfferPricing(t *testing.T) {
 	md := projectOfferPricing(entries)
 	for _, want := range []string{
 		"| Наименование | Рубли | Голоса в VK | Stars в Telegram |",
+		"| --- | ---: | ---: | ---: |", // price columns right-aligned
 		"| 50 «Фишек» | 200.00 | 30 | 100 |",
 		"| Наименование | «Фишки» |",
+		"| --- | ---: |",
 		"| 200 подсказок | 50 |",
 	} {
 		if !strings.Contains(md, want) {
@@ -44,6 +46,48 @@ func TestProjectOfferPricing(t *testing.T) {
 	}
 }
 
+// TestProjectOfferPricingOrdering checks packs sort by ascending rouble price, and values sort by
+// group (hints only → no-ads only → no-ads + hints) then ascending chip price within a group.
+func TestProjectOfferPricingOrdering(t *testing.T) {
+	pack := func(title string, rub int64) catalogEntry {
+		return catalogEntry{
+			id:     uuid.New(),
+			title:  title,
+			atoms:  []atomQty{{atomType: atomChips, quantity: 1}},
+			prices: []priceRow{{method: string(SourceDirect), currency: CurrencyRUB, amount: rub}},
+		}
+	}
+	value := func(title string, chips int64, atoms ...string) catalogEntry {
+		e := catalogEntry{id: uuid.New(), title: title, prices: []priceRow{{method: "", currency: CurrencyChip, amount: chips}}}
+		for _, a := range atoms {
+			e.atoms = append(e.atoms, atomQty{atomType: a, quantity: 1})
+		}
+		return e
+	}
+	// Deliberately out of order on input.
+	entries := []catalogEntry{
+		pack("packDear", 30000),
+		pack("packCheap", 10000),
+		value("bundle", 500, "hints", "noads_days"),
+		value("adsOnly", 150, "noads_days"),
+		value("hintsBig", 200, "hints"),
+		value("hintsSmall", 50, "hints"),
+	}
+	md := projectOfferPricing(entries)
+	order := []string{"packCheap", "packDear", "hintsSmall", "hintsBig", "adsOnly", "bundle"}
+	last := -1
+	for _, title := range order {
+		i := strings.Index(md, "| "+title+" |")
+		if i < 0 {
+			t.Fatalf("row %q missing:\n%s", title, md)
+		}
+		if i < last {
+			t.Errorf("row %q out of order (want sequence %v):\n%s", title, order, md)
+		}
+		last = i
+	}
+}
+
 // TestProjectOfferPricingMissingRailAndEscaping checks a pack missing a rail shows an em dash and a
 // title carrying a pipe is escaped so the table layout survives.
 func TestProjectOfferPricingMissingRailAndEscaping(t *testing.T) {