feat(admin): product catalog editor

The /_gm console gains a Catalog editor — the source of truth for products.
Create / edit / archive-unarchive products, their atom composition and per-rail
prices (RUB via direct / VOTE via vk / XTR via telegram / CHIP value), and
hard-delete only a never-transacted product (an order or ledger reference forces
archive-only, backed by the FK RESTRICT). The archived flag reuses the existing
product.active. Activation revalidates the sellable shape — a pack (the chips
atom ⇒ a money price per rail, chips-only) or a value (no chips ⇒ a CHIP price);
a tournament-bearing product is composable but never sellable yet.

Backed by payments AdminCatalog / CreateProduct / UpdateProduct /
SetProductActive / DeleteProduct + a pure validateProduct.

Tests: validateProduct (pack / value / tournament / duplicate / shape); the
console editor end to end (create, edit, archive, delete-if-clean, refuse a
transacted delete).

backend/internal/server/handlers_admin_catalog.go

@@ -0,0 +1,183 @@
+package server
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+
+	"scrabble/backend/internal/adminconsole"
+	"scrabble/backend/internal/payments"
+)
+
+// catalogBack is the product-list path the catalog console actions return to.
+const catalogBack = "/_gm/catalog"
+
+// atomField pairs a form field with its atom type; priceField pairs a form field with the payment
+// method + currency it prices, following the one-currency-per-rail mapping (direct→RUB, vk→VOTE,
+// telegram→XTR) plus the value's CHIP price (no method).
+var atomFields = []struct{ field, atom string }{
+	{"chips", "chips"}, {"hints", "hints"}, {"noads", "noads_days"}, {"tournament", "tournament"},
+}
+var priceFields = []struct {
+	field, method string
+	currency      payments.Currency
+}{
+	{"price_rub", "direct", payments.CurrencyRUB},
+	{"price_vote", "vk", payments.CurrencyVote},
+	{"price_star", "telegram", payments.CurrencyStar},
+	{"price_chip", "", payments.CurrencyChip},
+}
+
+// consoleCatalog lists every product (active and archived) with its composition, prices, transacted
+// flag, and the inline create form.
+func (s *Server) consoleCatalog(c *gin.Context) {
+	products, err := s.payments.AdminCatalog(c.Request.Context())
+	if err != nil {
+		s.consoleError(c, err)
+		return
+	}
+	var view adminconsole.CatalogView
+	for _, p := range products {
+		view.Products = append(view.Products, catalogRow(p))
+	}
+	s.renderConsole(c, "catalog", "catalog", "Catalog", view)
+}
+
+// catalogRow projects a product into its list row.
+func catalogRow(p payments.AdminProduct) adminconsole.ProductRow {
+	row := adminconsole.ProductRow{ID: p.ID.String(), Title: p.Title, Active: p.Active, Transacted: p.Transacted}
+	for _, a := range p.Atoms {
+		row.Atoms = append(row.Atoms, adminconsole.AtomRow{Atom: a.Atom, Quantity: a.Quantity})
+	}
+	for _, pr := range p.Prices {
+		row.Prices = append(row.Prices, adminconsole.PriceRow{Method: pr.Method, Currency: string(pr.Currency), Amount: pr.Amount})
+	}
+	return row
+}
+
+// consoleCatalogDetail renders one product's edit form, pre-filled from its current composition.
+func (s *Server) consoleCatalogDetail(c *gin.Context) {
+	id, ok := s.consoleUUID(c, catalogBack)
+	if !ok {
+		return
+	}
+	products, err := s.payments.AdminCatalog(c.Request.Context())
+	if err != nil {
+		s.consoleError(c, err)
+		return
+	}
+	for _, p := range products {
+		if p.ID == id {
+			s.renderConsole(c, "product_detail", "catalog", p.Title, productForm(p))
+			return
+		}
+	}
+	s.renderConsoleMessage(c, "Not found", "no such product", catalogBack)
+}
+
+// productForm builds the pre-filled edit form for a product.
+func productForm(p payments.AdminProduct) adminconsole.ProductFormView {
+	fv := adminconsole.ProductFormView{ID: p.ID.String(), Title: p.Title, Active: p.Active, Transacted: p.Transacted}
+	for _, a := range p.Atoms {
+		switch a.Atom {
+		case "chips":
+			fv.Chips = a.Quantity
+		case "hints":
+			fv.Hints = a.Quantity
+		case "noads_days":
+			fv.NoAds = a.Quantity
+		case "tournament":
+			fv.Tournament = a.Quantity
+		}
+	}
+	for _, pr := range p.Prices {
+		switch pr.Currency {
+		case payments.CurrencyRUB:
+			fv.PriceRUB = pr.Amount
+		case payments.CurrencyVote:
+			fv.PriceVote = pr.Amount
+		case payments.CurrencyStar:
+			fv.PriceStar = pr.Amount
+		case payments.CurrencyChip:
+			fv.PriceChip = pr.Amount
+		}
+	}
+	return fv
+}
+
+// parseProductForm reads a product's title, atoms, prices and active flag from the submitted form.
+func parseProductForm(c *gin.Context) (payments.ProductInput, bool) {
+	in := payments.ProductInput{Title: strings.TrimSpace(c.PostForm("title"))}
+	for _, a := range atomFields {
+		if q, err := strconv.Atoi(strings.TrimSpace(c.PostForm(a.field))); err == nil && q > 0 {
+			in.Atoms = append(in.Atoms, payments.AtomLine{Atom: a.atom, Quantity: q})
+		}
+	}
+	for _, p := range priceFields {
+		if amt, err := strconv.ParseInt(strings.TrimSpace(c.PostForm(p.field)), 10, 64); err == nil && amt > 0 {
+			in.Prices = append(in.Prices, payments.PriceLine{Method: p.method, Currency: p.currency, Amount: amt})
+		}
+	}
+	return in, c.PostForm("active") != ""
+}
+
+// consoleCreateProduct validates and inserts a new product from the create form.
+func (s *Server) consoleCreateProduct(c *gin.Context) {
+	in, active := parseProductForm(c)
+	if _, err := s.payments.CreateProduct(c.Request.Context(), in, active); err != nil {
+		s.renderConsoleMessage(c, "Invalid product", err.Error(), catalogBack)
+		return
+	}
+	s.renderConsoleMessage(c, "Created", "the product was created", catalogBack)
+}
+
+// consoleUpdateProduct validates and replaces a product's title, atoms and prices.
+func (s *Server) consoleUpdateProduct(c *gin.Context) {
+	id, ok := s.consoleUUID(c, catalogBack)
+	if !ok {
+		return
+	}
+	in, _ := parseProductForm(c)
+	back := catalogBack + "/" + id.String()
+	if err := s.payments.UpdateProduct(c.Request.Context(), id, in); err != nil {
+		s.renderConsoleMessage(c, "Invalid product", err.Error(), back)
+		return
+	}
+	s.renderConsoleMessage(c, "Saved", "the product was updated", back)
+}
+
+// consoleArchiveProduct archives or unarchives a product (the desired state rides in the form);
+// unarchiving revalidates the sellable shape.
+func (s *Server) consoleArchiveProduct(c *gin.Context) {
+	id, ok := s.consoleUUID(c, catalogBack)
+	if !ok {
+		return
+	}
+	active := c.PostForm("active") == "true"
+	if err := s.payments.SetProductActive(c.Request.Context(), id, active); err != nil {
+		s.renderConsoleMessage(c, "Cannot change status", err.Error(), catalogBack)
+		return
+	}
+	s.renderConsoleMessage(c, "Updated", "the product status was changed", catalogBack)
+}
+
+// consoleDeleteProductAction hard-deletes a never-transacted product; a transacted one is refused
+// with a hint to archive instead.
+func (s *Server) consoleDeleteProductAction(c *gin.Context) {
+	id, ok := s.consoleUUID(c, catalogBack)
+	if !ok {
+		return
+	}
+	err := s.payments.DeleteProduct(c.Request.Context(), id)
+	if errors.Is(err, payments.ErrProductTransacted) {
+		s.renderConsoleMessage(c, "Cannot delete", "this product has transactions; archive it instead", catalogBack)
+		return
+	}
+	if err != nil {
+		s.consoleError(c, err)
+		return
+	}
+	s.renderConsoleMessage(c, "Deleted", "the product was deleted", catalogBack)
+}

backend/internal/server/handlers_admin_console.go

@@ -102,6 +102,14 @@ func (s *Server) registerConsole(router *gin.Engine) {
 		gm.GET("/banner-settings", s.consoleBannerSettings)
 		gm.POST("/banner-settings", s.consoleUpdateBannerSettings)
 	}
+	if s.payments != nil {
+		gm.GET("/catalog", s.consoleCatalog)
+		gm.POST("/catalog", s.consoleCreateProduct)
+		gm.GET("/catalog/:id", s.consoleCatalogDetail)
+		gm.POST("/catalog/:id", s.consoleUpdateProduct)
+		gm.POST("/catalog/:id/archive", s.consoleArchiveProduct)
+		gm.POST("/catalog/:id/delete", s.consoleDeleteProductAction)
+	}
 }
 
 // consoleDashboard renders the landing page: the top-line counts and the resident