fix(admin): shorten the receipt letter, show the account id

The receipt letter repeated what the receipt itself states. It now carries the
amount, the moment of payment with its offset, and the link — the receipt is
the document, and it opens without authentication, so there is nothing for the
two to disagree about. Subject reworded to name what it is.

The ledger and tax-export tables labelled the account link "card", meaning the
user card. On pages about payments that reads as a bank card, which is exactly
how it was misread. Both now show the first eight characters of the account id,
so the column carries data — two rows from the same buyer are visible at a
glance — while the link still holds the whole id.

.claude/CLAUDE.md

@@ -292,6 +292,10 @@ The native Android app is a Capacitor 8 wrapper of the `ui` SPA, scaffolded unde
     millisecond clock — the first eight are shared by every order in the same ~65 seconds, which
     would make two purchases indistinguishable to the probe. An unresolved outcome halts the
     whole queue on purpose; a blind retry is the one thing that must never happen.
+  - **The printable receipt link IS public** — `GET /api/v1/receipt/<ИНН>/<uuid>/print` opens with
+    no authentication (verified on prod 2026-07-28; online sources contradict each other on this,
+    so do not "fix" it back). It is the same URL the «Мой налог» app hands out under «копировать в
+    буфер», which is why the buyer's receipt letter can simply carry it.
   - **The receipt's time zone decides the tax month.** The ledger is UTC; `BACKEND_MYNALOG_TZ`
     (default `Europe/Moscow`) is what a payment is filed under, so a 23:30 UTC payment on the last
     of the month belongs to the *next* one.

backend/internal/adminconsole/render_test.go

@@ -54,10 +54,10 @@ func TestRendererRendersEveryPage(t *testing.T) {
 			SignedIn: true, INN: "770000000000", AutoEnabled: true, TimeZone: "Europe/Moscow",
 			LastOK:  "2026-07-28 12:00",
 			Backlog: MyNalogBacklogRow{Count: 2, Amount: "300.00 RUB", Oldest: "2026-06-30", Overdue: true},
-			Owed: []MyNalogRow{{LedgerID: "l1", AccountID: "a1", At: "2026-07-28 12:00",
+			Owed: []MyNalogRow{{LedgerID: "l1", AccountID: "a1", AccountShort: "a1", At: "2026-07-28 12:00",
 				Amount: "149.00 RUB", Name: `Внутриигровая валюта: "Фишка", 100 шт. (ID: 0198c1f2)`}},
-			Cancels: []MyNalogCancelRow{{LedgerID: "l2", AccountID: "a2", ReceiptUUID: "20abcdef01", Failed: true}},
-			Attention: []MyNalogRow{{LedgerID: "l3", AccountID: "a3", At: "2026-07-27 09:00",
+			Cancels: []MyNalogCancelRow{{LedgerID: "l2", AccountID: "a2", AccountShort: "a2", ReceiptUUID: "20abcdef01", Failed: true}},
+			Attention: []MyNalogRow{{LedgerID: "l3", AccountID: "a3", AccountShort: "a3", At: "2026-07-27 09:00",
 				Amount: "99.00 RUB", Name: "x (ID: 0198c1f3)", Attempts: 2, LastError: "timeout"}},
 		}, "Needs attention"},
 		{"mynalog", MyNalogView{SignedIn: true, TimeZone: "Europe/Moscow", Paused: true,

backend/internal/adminconsole/templates/pages/ledger.gohtml

@@ -40,7 +40,7 @@ Money in: {{range .Totals.MoneyIn}}<strong>{{.}}</strong> {{else}}<span class="n
 {{range .Rows}}
 <tr>
 <td>{{.At}}</td>
-<td><a href="/_gm/users/{{.AccountID}}">card</a></td>
+<td><a href="/_gm/users/{{.AccountID}}"><code>{{.AccountShort}}</code></a></td>
 <td>{{.Kind}}</td>
 <td>{{.Money}}</td>
 <td>{{.ChipsDelta}}</td>

backend/internal/adminconsole/templates/pages/mynalog.gohtml

@@ -79,7 +79,7 @@ created; entering a receipt number means you filed it by hand.</p>
 <tbody>
 {{range .Cancels}}
 <tr>
-<td><a href="/_gm/users/{{.AccountID}}">card</a></td>
+<td><a href="/_gm/users/{{.AccountID}}"><code>{{.AccountShort}}</code></a></td>
 <td><code>{{.ReceiptUUID}}</code></td>
 <td>{{if .Failed}}<span class="note">a previous attempt was refused</span>{{else}}awaiting{{end}}</td>
 </tr>
@@ -96,7 +96,7 @@ created; entering a receipt number means you filed it by hand.</p>
 {{range .Owed}}
 <tr>
 <td>{{.At}}</td>
-<td><a href="/_gm/users/{{.AccountID}}">card</a></td>
+<td><a href="/_gm/users/{{.AccountID}}"><code>{{.AccountShort}}</code></a></td>
 <td class="num">{{.Amount}}</td>
 <td><code>{{.Name}}</code></td>
 <td class="num">{{.Attempts}}</td>

backend/internal/adminconsole/views.go

@@ -786,7 +786,10 @@ type LedgerView struct {
 // still reverse, which is what puts the Refund button on that row.
 type LedgerRow struct {
 	At string
+	// AccountID is the link target; AccountShort is what the cell shows, because a ledger row has
+	// no room for a full uuid and the operator mostly needs to spot two rows from the same buyer.
 	AccountID    string
+	AccountShort string
 	Kind         string
 	Source       string
 	Origin       string
@@ -843,6 +846,7 @@ type MyNalogBacklogRow struct {
 type MyNalogRow struct {
 	LedgerID     string
 	AccountID    string
+	AccountShort string
 	At           string
 	Amount       string
 	Name         string
@@ -858,6 +862,7 @@ type MyNalogRow struct {
 type MyNalogCancelRow struct {
 	LedgerID     string
 	AccountID    string
+	AccountShort string
 	ReceiptUUID  string
 	Failed       bool
 }

backend/internal/inttest/mynalog_test.go

@@ -675,8 +675,22 @@ func TestMyNalogBuyerMails(t *testing.T) {
 	if got := len(box.to(addr)); got != 2 {
 		t.Fatalf("letters after filing = %d, want 2", got)
 	}
-	if !strings.Contains(box.to(addr)[1].Text, "/api/v1/receipt/770000000000/") {
-		t.Errorf("the receipt letter carries no receipt link:\n%s", box.to(addr)[1].Text)
+	receipt := box.to(addr)[1]
+	if receipt.Subject != "Эрудит — Ваш чек покупки" {
+		t.Errorf("receipt letter subject = %q", receipt.Subject)
+	}
+	if !strings.Contains(receipt.Text, "/api/v1/receipt/770000000000/") {
+		t.Errorf("the receipt letter carries no receipt link:\n%s", receipt.Text)
+	}
+	// The amount carries its time-zone offset, because that offset is what decides the tax period
+	// the receipt belongs to and the buyer should see the same moment the receipt states.
+	if !strings.Contains(receipt.Text, "Покупка на сумму: 149.00 ₽ от ") ||
+		!strings.Contains(receipt.Text, "+03:00") {
+		t.Errorf("the receipt letter's amount line is wrong:\n%s", receipt.Text)
+	}
+	// Nothing beyond the amount, the moment and the link: the receipt is the document.
+	if strings.Contains(receipt.Text, "test pack") {
+		t.Errorf("the receipt letter repeats the catalog title; the receipt itself carries it:\n%s", receipt.Text)
 	}
 
 	// 3. The annulment letter after a refund.

backend/internal/mynalogsync/mailer.go

@@ -164,7 +164,7 @@ func (m *Mailer) sendReceiptMails(ctx context.Context, cancelled bool) {
 			m.stampReceipt(ctx, mark, r.LedgerID)
 			continue
 		}
-		subject, body := "Эрудит — чек от налоговой", receiptText(r, stored.INN, m.baseURL, m.loc)
+		subject, body := "Эрудит — Ваш чек покупки", receiptText(r, stored.INN, m.baseURL, m.loc)
 		if cancelled {
 			subject, body = "Эрудит — чек аннулирован", cancelText(r, m.loc)
 		}
@@ -232,19 +232,19 @@ func purchaseText(p payments.PurchaseMail) string {
 
 // receiptText is the fiscal receipt letter, which is how the receipt is actually handed to the
 // buyer as the professional-income tax regime requires.
+//
+// It is deliberately bare: the amount, the moment of payment with its offset, and the link. The
+// receipt itself is the document and it opens without authentication, so repeating its contents
+// here would only add something for the two to disagree about.
 func receiptText(r payments.ReceiptMail, inn, baseURL string, loc *time.Location) string {
 	return fmt.Sprintf(`Здравствуйте!
 
-По вашей покупке сформирован чек в налоговой службе.
+Покупка на сумму: %s от %s
+Ссылка на чек: %s
 
-%s
-Дата: %s
-Чек: %s
-
-Продавец применяет налог на профессиональный доход; чек сформирован в сервисе
-«Мой налог» Федеральной налоговой службы.
-`, describe(r.Title, r.AmountMinor, r.Currency),
-		r.OperationTime.In(loc).Format("02.01.2006 15:04"),
+Спасибо, что играете в «Эрудит».
+`, formatAmount(r.AmountMinor, r.Currency),
+		r.OperationTime.In(loc).Format("02.01.2006 15:04 -07:00"),
 		mynalog.ReceiptURL(baseURL, inn, r.ReceiptUUID))
 }
 

backend/internal/server/handlers_admin_console.go

@@ -1375,6 +1375,17 @@ func normalizeComplaintStatus(s string) string {
 	return ""
 }
 
+// shortID abbreviates an account id for a table cell: enough to recognise the same buyer across
+// rows at a glance, while the link still carries the whole id. Money tables have no room for a full
+// uuid, and a generic label there ("card") read as a payment card on the very pages about payments.
+func shortID(id string) string {
+	const n = 8
+	if len(id) <= n {
+		return id
+	}
+	return id[:n]
+}
+
 // fmtTime formats a timestamp for display, or "" when zero.
 func fmtTime(t time.Time) string {
 	if t.IsZero() {

backend/internal/server/handlers_admin_ledger.go

@@ -132,6 +132,7 @@ func ledgerRow(r payments.LedgerReportRow) adminconsole.LedgerRow {
 	row := adminconsole.LedgerRow{
 		At:           fmtTime(r.CreatedAt),
 		AccountID:    r.AccountID.String(),
+		AccountShort: shortID(r.AccountID.String()),
 		Kind:         r.Kind,
 		Source:       r.Source,
 		Origin:       r.Origin,

backend/internal/server/handlers_admin_mynalog.go

@@ -61,6 +61,7 @@ func (s *Server) consoleMyNalog(c *gin.Context) {
 		view.Cancels = append(view.Cancels, adminconsole.MyNalogCancelRow{
 			LedgerID:     cn.LedgerID.String(),
 			AccountID:    cn.AccountID.String(),
+			AccountShort: shortID(cn.AccountID.String()),
 			ReceiptUUID:  cn.ReceiptUUID,
 			Failed:       cn.CancelStatus == payments.MyNalogCancelFailed,
 		})
@@ -99,6 +100,7 @@ func (s *Server) myNalogRow(in payments.MyNalogIncome, inn string, loc *time.Loc
 	row := adminconsole.MyNalogRow{
 		LedgerID:     in.LedgerID.String(),
 		AccountID:    in.AccountID.String(),
+		AccountShort: shortID(in.AccountID.String()),
 		At:           in.OperationTime.In(loc).Format("2006-01-02 15:04"),
 		Amount:       in.Amount.String(),
 		Name:         s.mynalog.ReceiptName(in),