feat(payments): wallet screen with balances, benefits and storefront

Add the "Кошелёк" section to the settings hub: context-visible chip
balances, active benefits (no-ads term/forever, hints) and a storefront of
chip-priced values and money-priced chip packs. Guests have no wallet; the
Google Play build hides the money purchases behind a RuStore stub; a web
purchase that would draw VK/Telegram chips warns first.

Add the catalog read path the storefront needs — a context-projected
GET /api/v1/user/wallet/catalog (payments service + store, gateway op
wallet.catalog, FBS Catalog/CatalogProduct/CatalogAtom, client decode) —
plus the client leg for the existing wallet.get/buy ops. Value spends reuse
the existing spend path; the chip-pack purchase (money order flow) arrives
with payment intake, so its action is a disabled placeholder for now.

Covered by Go unit (catalog projection) + integration (/wallet/catalog over
Postgres), vitest (formatting, spendable selection, web-spend warning, GP
flag, codec + gateway encode round-trips) and Playwright mock e2e (render,
guest-hidden, GP stub, warning) on Chromium + WebKit.

backend/README.md

@@ -100,7 +100,10 @@ state, lobby enqueue, chat). The social/account/history operations under
 `/api/v1/user`: `friends/*` (request/respond/cancel/unfriend,
 list/incoming, the one-time `code` issue/redeem), `blocks/*`, `invitations/*`
 (create/accept/decline/cancel/list), `PUT profile`, `email/{request,confirm}`,
-`stats`, and `games/:id/gcg` (finished-only). The `internal/notify` hub feeds a
+`stats`, `games/:id/gcg` (finished-only), and the payments `wallet` /
+`wallet/catalog` (`GET` — the context-visible chip segments + benefits, and the
+storefront catalog) / `wallet/buy` (`POST` — a chip spend on a value), served by
+`internal/payments` behind the store-compliance gate. The `internal/notify` hub feeds a
 second listener — `internal/pushgrpc`, a gRPC server (`BACKEND_GRPC_ADDR`) streaming
 live events (your-turn, opponent-moved, chat, nudge, match-found, notify) to the
 gateway. The gateway-only `POST /api/v1/internal/push-target` (a user's

backend/internal/inttest/payments_catalog_test.go

@@ -0,0 +1,113 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/payments"
+)
+
+// methodPrice is one per-method money price for a seeded chip pack.
+type methodPrice struct {
+	method   string
+	currency string
+	amount   int64
+}
+
+// seedPackProduct creates an active chip pack: a product carrying the chips atom and a money price
+// per method. It returns the product id.
+func seedPackProduct(t *testing.T, chips int, prices ...methodPrice) uuid.UUID {
+	t.Helper()
+	ctx := context.Background()
+	prod := uuid.New()
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product (product_id, title, active) VALUES ($1,'test pack',true)`, prod); err != nil {
+		t.Fatalf("seed pack product: %v", err)
+	}
+	if _, err := testDB.ExecContext(ctx,
+		`INSERT INTO payments.product_item (product_id, atom_type, quantity) VALUES ($1,'chips',$2)`, prod, chips); err != nil {
+		t.Fatalf("seed chips item: %v", err)
+	}
+	for _, p := range prices {
+		if _, err := testDB.ExecContext(ctx,
+			`INSERT INTO payments.product_price (product_id, method, currency, amount) VALUES ($1,$2,$3,$4)`,
+			prod, p.method, p.currency, p.amount); err != nil {
+			t.Fatalf("seed pack price %s: %v", p.method, err)
+		}
+	}
+	return prod
+}
+
+// findCatalogProduct returns the projected storefront product for id in the context (the catalog
+// is global, so tests assert by id rather than count — testDB is shared).
+func findCatalogProduct(t *testing.T, svc *payments.Service, cxt payments.Context, id uuid.UUID) (payments.CatalogProduct, bool) {
+	t.Helper()
+	view, err := svc.Catalog(context.Background(), cxt)
+	if err != nil {
+		t.Fatalf("catalog: %v", err)
+	}
+	for _, p := range view.Products {
+		if p.ProductID == id.String() {
+			return p, true
+		}
+	}
+	return payments.CatalogProduct{}, false
+}
+
+// TestPaymentsCatalogByContext verifies the storefront projects a value at its chip price in every
+// context and a chip pack at the context method's money price, over Postgres.
+func TestPaymentsCatalogByContext(t *testing.T) {
+	svc := newPaymentsService()
+	value := seedValueProduct(t, 500, 250, 0)
+	pack := seedPackProduct(t, 100,
+		methodPrice{"vk", "VOTE", 20},
+		methodPrice{"telegram", "XTR", 25},
+		methodPrice{"direct", "RUB", 14900},
+	)
+
+	for _, kind := range []string{"vk", "telegram", "direct"} {
+		v, ok := findCatalogProduct(t, svc, payments.NewContext(kind, "web"), value)
+		if !ok {
+			t.Fatalf("value missing in %s context", kind)
+		}
+		if v.Kind != "value" || v.Chips != 500 || v.MoneyCurrency != "" {
+			t.Errorf("value in %s = %+v, want kind=value chips=500 no money", kind, v)
+		}
+	}
+
+	cases := []struct {
+		kind     string
+		amount   int64
+		currency string
+	}{
+		{"vk", 20, "VOTE"},
+		{"telegram", 25, "XTR"},
+		{"direct", 14900, "RUB"},
+	}
+	for _, tc := range cases {
+		p, ok := findCatalogProduct(t, svc, payments.NewContext(tc.kind, "web"), pack)
+		if !ok {
+			t.Fatalf("pack missing in %s context", tc.kind)
+		}
+		if p.Kind != "pack" || p.Chips != 0 || p.MoneyAmount != tc.amount || p.MoneyCurrency != tc.currency {
+			t.Errorf("pack in %s = %+v, want kind=pack amount=%d currency=%s", tc.kind, p, tc.amount, tc.currency)
+		}
+	}
+}
+
+// TestPaymentsCatalogExcludesDeactivated verifies a soft-deleted product drops out of the storefront.
+func TestPaymentsCatalogExcludesDeactivated(t *testing.T) {
+	svc := newPaymentsService()
+	prod := seedValueProduct(t, 100, 10, 0)
+	if _, err := testDB.ExecContext(context.Background(),
+		`UPDATE payments.product SET active=false WHERE product_id=$1`, prod); err != nil {
+		t.Fatalf("deactivate: %v", err)
+	}
+	if _, ok := findCatalogProduct(t, svc, payments.NewContext("direct", "web"), prod); ok {
+		t.Error("deactivated product must not appear in the storefront")
+	}
+}

backend/internal/payments/catalog.go

@@ -0,0 +1,82 @@
+package payments
+
+// AtomQty is one atom line of a catalog product in the read model: the base value type it grants
+// (chips / hints / no-ads days / tournament) and how many of it the product carries.
+type AtomQty struct {
+	AtomType string
+	Quantity int
+}
+
+// CatalogProduct is one storefront product projected for the execution context. A value is
+// bought with chips, so it carries Chips (its uniform chip price) and no money price. A chip pack
+// funds chips with money, so it carries MoneyAmount (minor units) and MoneyCurrency for the
+// context's payment method and no chip price. Atoms lists what the product grants.
+type CatalogProduct struct {
+	Kind          string // "value" (bought with chips) or "pack" (funds chips with money)
+	ProductID     string
+	Title         string
+	Chips         int    // a value's uniform chip price; 0 for a pack
+	MoneyAmount   int64  // a pack's price in the context currency's minor units; 0 for a value
+	MoneyCurrency string // a pack's currency for the context method; empty for a value
+	Atoms         []AtomQty
+}
+
+// CatalogView is the storefront read model for one execution context: the products a player sees
+// and can buy there — every chip-priced value plus the chip packs priced in the context's method.
+type CatalogView struct {
+	Products []CatalogProduct
+}
+
+// atomChips is the atom type that marks a product as a chip pack (it funds chips) rather than a
+// value (bought with chips). A value never carries it.
+const atomChips = "chips"
+
+// projectCatalog turns the raw active catalog into the storefront for the context. A value (no
+// chips atom) is shown everywhere at its CHIP price. A chip pack is shown only when it carries a
+// price for the context's payment method (cxt.Kind: vk / telegram / direct), priced in that
+// method's currency. A value missing its CHIP price and a pack missing a price for the context
+// method are omitted (misconfigured or unavailable there). An untrusted context (empty Kind) has
+// no method, so only values show; buying is gated server-side regardless.
+func projectCatalog(entries []catalogEntry, cxt Context) CatalogView {
+	var out CatalogView
+	for _, e := range entries {
+		isPack := false
+		atoms := make([]AtomQty, 0, len(e.atoms))
+		for _, a := range e.atoms {
+			atoms = append(atoms, AtomQty{AtomType: a.atomType, Quantity: a.quantity})
+			if a.atomType == atomChips {
+				isPack = true
+			}
+		}
+		p := CatalogProduct{ProductID: e.id.String(), Title: e.title, Atoms: atoms}
+		if isPack {
+			pr, ok := findPrice(e.prices, string(cxt.Kind))
+			if !ok {
+				continue // no price for this context's method — not purchasable here
+			}
+			p.Kind = "pack"
+			p.MoneyAmount = pr.amount
+			p.MoneyCurrency = string(pr.currency)
+		} else {
+			pr, ok := findPrice(e.prices, "")
+			if !ok {
+				continue // a value must carry a CHIP price
+			}
+			p.Kind = "value"
+			p.Chips = int(pr.amount)
+		}
+		out.Products = append(out.Products, p)
+	}
+	return out
+}
+
+// findPrice returns the price row for the given payment method — the empty string selects a
+// value's CHIP price row (stored with a NULL method).
+func findPrice(prices []priceRow, method string) (priceRow, bool) {
+	for _, pr := range prices {
+		if pr.method == method {
+			return pr, true
+		}
+	}
+	return priceRow{}, false
+}

backend/internal/payments/catalog_test.go

@@ -0,0 +1,136 @@
+package payments
+
+import (
+	"testing"
+
+	"github.com/google/uuid"
+)
+
+// catalog fixtures: a chip-priced value (hints), a multi-method chip pack, a VK-only chip pack, a
+// value with no CHIP price (misconfigured), and a pack whose only method is telegram.
+func fixtureCatalog() []catalogEntry {
+	value := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000001"),
+		title: "250 hints",
+		atoms: []atomQty{{atomType: "hints", quantity: 250}},
+		prices: []priceRow{
+			{method: "", currency: CurrencyChip, amount: 500},
+		},
+	}
+	pack := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000002"),
+		title: "100 chips",
+		atoms: []atomQty{{atomType: "chips", quantity: 100}},
+		prices: []priceRow{
+			{method: "vk", currency: CurrencyVote, amount: 20},
+			{method: "telegram", currency: CurrencyStar, amount: 25},
+			{method: "direct", currency: CurrencyRUB, amount: 14900},
+		},
+	}
+	vkOnlyPack := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000003"),
+		title: "VK-only chips",
+		atoms: []atomQty{{atomType: "chips", quantity: 50}},
+		prices: []priceRow{
+			{method: "vk", currency: CurrencyVote, amount: 10},
+		},
+	}
+	brokenValue := catalogEntry{
+		id:    uuid.MustParse("00000000-0000-0000-0000-000000000004"),
+		title: "no chip price",
+		atoms: []atomQty{{atomType: "noads_days", quantity: 30}},
+		// no CHIP price row — misconfigured, must be omitted
+	}
+	return []catalogEntry{value, pack, vkOnlyPack, brokenValue}
+}
+
+// byID indexes a projected storefront by product id for assertions.
+func byID(v CatalogView) map[string]CatalogProduct {
+	m := make(map[string]CatalogProduct, len(v.Products))
+	for _, p := range v.Products {
+		m[p.ProductID] = p
+	}
+	return m
+}
+
+func TestProjectCatalog_ContextMatrix(t *testing.T) {
+	const (
+		valueID  = "00000000-0000-0000-0000-000000000001"
+		packID   = "00000000-0000-0000-0000-000000000002"
+		vkPackID = "00000000-0000-0000-0000-000000000003"
+		brokenID = "00000000-0000-0000-0000-000000000004"
+	)
+	entries := fixtureCatalog()
+
+	tests := []struct {
+		name        string
+		cxt         Context
+		wantPackAmt int64
+		wantPackCur Currency
+		wantVKPack  bool // the vk-only pack visible?
+	}{
+		{"vk", Context{Kind: SourceVK}, 20, CurrencyVote, true},
+		{"vk-ios frozen still lists vk price", Context{Kind: SourceVK, Subtype: SubtypeIOS}, 20, CurrencyVote, true},
+		{"telegram", Context{Kind: SourceTelegram}, 25, CurrencyStar, false},
+		{"direct", Context{Kind: SourceDirect}, 14900, CurrencyRUB, false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := byID(projectCatalog(entries, tc.cxt))
+
+			// The value shows everywhere at its uniform chip price, never a money price.
+			v, ok := got[valueID]
+			if !ok {
+				t.Fatalf("value missing from %s storefront", tc.name)
+			}
+			if v.Kind != "value" || v.Chips != 500 || v.MoneyCurrency != "" || v.MoneyAmount != 0 {
+				t.Errorf("value = %+v, want kind=value chips=500 no money", v)
+			}
+			if len(v.Atoms) != 1 || v.Atoms[0].AtomType != "hints" || v.Atoms[0].Quantity != 250 {
+				t.Errorf("value atoms = %+v, want [hints:250]", v.Atoms)
+			}
+
+			// The multi-method pack shows the context method's price, in that currency, no chips.
+			p, ok := got[packID]
+			if !ok {
+				t.Fatalf("pack missing from %s storefront", tc.name)
+			}
+			if p.Kind != "pack" || p.Chips != 0 || p.MoneyAmount != tc.wantPackAmt || p.MoneyCurrency != string(tc.wantPackCur) {
+				t.Errorf("pack = %+v, want kind=pack amount=%d currency=%s", p, tc.wantPackAmt, tc.wantPackCur)
+			}
+
+			// The vk-only pack shows only where a vk price exists.
+			if _, ok := got[vkPackID]; ok != tc.wantVKPack {
+				t.Errorf("vk-only pack present=%v, want %v (%s)", ok, tc.wantVKPack, tc.name)
+			}
+
+			// The misconfigured value (no CHIP price) is never shown.
+			if _, ok := got[brokenID]; ok {
+				t.Errorf("misconfigured value must be omitted (%s)", tc.name)
+			}
+		})
+	}
+}
+
+// An untrusted context (empty Kind) has no payment method, so it shows values only — no packs.
+func TestProjectCatalog_UntrustedShowsValuesOnly(t *testing.T) {
+	got := byID(projectCatalog(fixtureCatalog(), Context{}))
+	if _, ok := got["00000000-0000-0000-0000-000000000001"]; !ok {
+		t.Error("untrusted context should still list the chip-priced value")
+	}
+	for _, id := range []string{
+		"00000000-0000-0000-0000-000000000002",
+		"00000000-0000-0000-0000-000000000003",
+	} {
+		if _, ok := got[id]; ok {
+			t.Errorf("untrusted context must not list pack %s", id)
+		}
+	}
+}
+
+// An empty catalog projects to an empty storefront (no products seeded yet — the Release-1 state).
+func TestProjectCatalog_Empty(t *testing.T) {
+	if got := projectCatalog(nil, Context{Kind: SourceDirect}); len(got.Products) != 0 {
+		t.Errorf("empty catalog projected %d products, want 0", len(got.Products))
+	}
+}

backend/internal/payments/service.go

@@ -54,6 +54,18 @@ func (s *Service) Wallet(ctx context.Context, accountID uuid.UUID, cxt Context,
 	return view, nil
 }
 
+// Catalog returns the storefront for the execution context: every chip-priced value (shown in
+// every context) plus the chip packs priced in the context's payment method. It is read straight
+// from the catalog tables — small and rarely edited, so uncached. An untrusted context has no
+// method and so shows values only; buying is gate-checked on Spend regardless (fail-closed).
+func (s *Service) Catalog(ctx context.Context, cxt Context) (CatalogView, error) {
+	entries, err := s.store.loadCatalog(ctx)
+	if err != nil {
+		return CatalogView{}, err
+	}
+	return projectCatalog(entries, cxt), nil
+}
+
 // AdFree reports whether ads are suppressed for the account in the context: some origin
 // applicable there has an active no-ads term or the forever flag. Fail-closed on an untrusted
 // platform (no origin applies).

backend/internal/payments/store_catalog.go

@@ -0,0 +1,89 @@
+package payments
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/postgres/jet/payments/model"
+	"scrabble/backend/internal/postgres/jet/payments/table"
+)
+
+// atomQty is one atom line of a product as loaded from the catalog: the atom type and quantity.
+type atomQty struct {
+	atomType string
+	quantity int
+}
+
+// priceRow is one price of a product as loaded from the catalog: the payment method (empty for a
+// value's CHIP price, stored with a NULL method) and the amount in that currency's minor units.
+type priceRow struct {
+	method   string
+	currency Currency
+	amount   int64
+}
+
+// catalogEntry is a raw active product loaded for the storefront: its atom composition and every
+// price row. [projectCatalog] turns it into the context-visible [CatalogProduct].
+type catalogEntry struct {
+	id     uuid.UUID
+	title  string
+	atoms  []atomQty
+	prices []priceRow
+}
+
+// loadCatalog reads every active product with its atoms and prices, ordered by creation, straight
+// from the catalog tables. The catalog is small and rarely edited (admin console only), so it is
+// read uncached — unlike the per-account balances/benefits the read cache fronts.
+func (s *Store) loadCatalog(ctx context.Context) ([]catalogEntry, error) {
+	var prods []model.Product
+	if err := postgres.SELECT(table.Product.AllColumns).
+		FROM(table.Product).
+		WHERE(table.Product.Active.IS_TRUE()).
+		ORDER_BY(table.Product.CreatedAt.ASC()).
+		QueryContext(ctx, s.db, &prods); err != nil {
+		return nil, fmt.Errorf("payments: load catalog products: %w", err)
+	}
+	if len(prods) == 0 {
+		return nil, nil
+	}
+	entries := make([]catalogEntry, len(prods))
+	index := make(map[uuid.UUID]int, len(prods))
+	for i, p := range prods {
+		entries[i] = catalogEntry{id: p.ProductID, title: p.Title}
+		index[p.ProductID] = i
+	}
+
+	var items []model.ProductItem
+	if err := postgres.SELECT(table.ProductItem.AllColumns).
+		FROM(table.ProductItem).
+		QueryContext(ctx, s.db, &items); err != nil {
+		return nil, fmt.Errorf("payments: load catalog items: %w", err)
+	}
+	for _, it := range items {
+		if i, ok := index[it.ProductID]; ok {
+			entries[i].atoms = append(entries[i].atoms, atomQty{atomType: it.AtomType, quantity: int(it.Quantity)})
+		}
+	}
+
+	var prices []model.ProductPrice
+	if err := postgres.SELECT(table.ProductPrice.AllColumns).
+		FROM(table.ProductPrice).
+		QueryContext(ctx, s.db, &prices); err != nil {
+		return nil, fmt.Errorf("payments: load catalog prices: %w", err)
+	}
+	for _, pr := range prices {
+		i, ok := index[pr.ProductID]
+		if !ok {
+			continue // a price for a deactivated product — not in the storefront
+		}
+		method := ""
+		if pr.Method != nil {
+			method = *pr.Method
+		}
+		entries[i].prices = append(entries[i].prices, priceRow{method: method, currency: Currency(pr.Currency), amount: pr.Amount})
+	}
+	return entries, nil
+}

backend/internal/server/handlers.go

@@ -67,8 +67,10 @@ func (s *Server) registerRoutes() {
 		u.GET("/block-status", s.handleBlockStatus)
 	}
 	if s.payments != nil {
-		// The wallet: the context-visible chip segments + benefits, and a chip spend on a value.
+		// The wallet: the context-visible chip segments + benefits, the storefront catalog, and a
+		// chip spend on a value.
 		u.GET("/wallet", s.handleWallet)
+		u.GET("/wallet/catalog", s.handleWalletCatalog)
 		u.POST("/wallet/buy", s.handleWalletBuy)
 	}
 	if s.links != nil {

backend/internal/server/handlers_wallet.go

@@ -45,6 +45,68 @@ func walletDTOFrom(v payments.WalletView) walletDTO {
 	return out
 }
 
+// catalogAtomDTO is one atom line of a storefront product: the base value type it grants and how
+// many of it the product carries.
+type catalogAtomDTO struct {
+	AtomType string `json:"atom_type"`
+	Quantity int    `json:"quantity"`
+}
+
+// catalogProductDTO is one storefront product for the caller's context: a chip-priced value
+// (chips set, no money price) or a chip pack priced in the context's payment method
+// (money_amount minor units + money_currency, no chips), plus what it grants.
+type catalogProductDTO struct {
+	Kind          string           `json:"kind"`
+	ProductID     string           `json:"product_id"`
+	Title         string           `json:"title"`
+	Chips         int              `json:"chips"`
+	MoneyAmount   int64            `json:"money_amount"`
+	MoneyCurrency string           `json:"money_currency"`
+	Atoms         []catalogAtomDTO `json:"atoms"`
+}
+
+// catalogDTO is the storefront: the products visible and purchasable in the caller's context.
+type catalogDTO struct {
+	Products []catalogProductDTO `json:"products"`
+}
+
+// catalogDTOFrom projects a payments catalog view into the wire DTO.
+func catalogDTOFrom(v payments.CatalogView) catalogDTO {
+	out := catalogDTO{Products: make([]catalogProductDTO, 0, len(v.Products))}
+	for _, p := range v.Products {
+		atoms := make([]catalogAtomDTO, 0, len(p.Atoms))
+		for _, a := range p.Atoms {
+			atoms = append(atoms, catalogAtomDTO{AtomType: a.AtomType, Quantity: a.Quantity})
+		}
+		out.Products = append(out.Products, catalogProductDTO{
+			Kind: p.Kind, ProductID: p.ProductID, Title: p.Title,
+			Chips: p.Chips, MoneyAmount: p.MoneyAmount, MoneyCurrency: p.MoneyCurrency, Atoms: atoms,
+		})
+	}
+	return out
+}
+
+// handleWalletCatalog returns the storefront for the caller's trusted execution context: the
+// chip-priced values and the chip packs priced in the context's payment method.
+func (s *Server) handleWalletCatalog(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		return
+	}
+	ctx := c.Request.Context()
+	cxt, _, err := s.walletGate(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	view, err := s.payments.Catalog(ctx, cxt)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, catalogDTOFrom(view))
+}
+
 // handleWallet returns the caller's wallet — the segments and benefits visible in the current
 // trusted execution context.
 func (s *Server) handleWallet(c *gin.Context) {