feat(telegram,game): single bot + per-user variant preferences

Collapse the two per-language Telegram bots into one unified bot and
replace language-based variant gating with explicit per-user variant
preferences.

- Telegram: one bot; drop service_language and the supported_languages
  set everywhere (DB, account, auth, FlatBuffers Session wire, gateway,
  connector proto). The single bot renders chat and out-of-app push in
  the recipient's preferred_language; remove the game-language push
  routing override (notify Intent.Language / push Event.language).
- Preferences: new accounts.variant_preferences (text[], DB default
  {erudit_ru}, CHECK non-empty + subset of the three variants). Gates
  the New Game picker, vs-AI and the friend invitation the player
  creates, enforced server-side (HTTP 400 otherwise); an invited friend
  may still accept any variant. Edited on the Settings screen; variants
  are Erudit-first everywhere.
- Admin: drop the per-bot language selectors (broadcast / send-to-user)
  and the feedback channel_lang column/field.
- Env/CI: collapse TELEGRAM_BOT_TOKEN_{EN,RU}, TELEGRAM_GAME_CHANNEL_ID_{EN,RU},
  VITE_TELEGRAM_LINK{,_EN,_RU} and VITE_TELEGRAM_GAME_CHANNEL_NAME_{EN,RU}
  to single unsuffixed names; drop GATEWAY_DEFAULT_SUPPORTED_LANGUAGES.
- Docs updated (ARCHITECTURE, FUNCTIONAL + _ru, platform/telegram, gateway,
  backend, ui, UI_DESIGN, PRERELEASE).

The migration squash is deferred to a follow-up PR.

pkg/proto/push/v1/push.pb.go

@@ -79,16 +79,11 @@ func (x *SubscribeRequest) GetGatewayId() string {
 // FlatBuffers-encoded body for that kind. event_id is a correlation id the
 // gateway carries through to the client envelope.
 type Event struct {
-	state   protoimpl.MessageState `protogen:"open.v1"`
-	UserId  string                 `protobuf:"bytes,1,opt,name=user_id,json=userId,proto3" json:"user_id,omitempty"`
-	Kind    string                 `protobuf:"bytes,2,opt,name=kind,proto3" json:"kind,omitempty"`
-	Payload []byte                 `protobuf:"bytes,3,opt,name=payload,proto3" json:"payload,omitempty"`
-	EventId string                 `protobuf:"bytes,4,opt,name=event_id,json=eventId,proto3" json:"event_id,omitempty"`
-	// language routes an out-of-app push to a specific per-language bot: for a game
-	// event it carries the game's language ("en"/"ru") so the notification comes from the game's
-	// bot rather than the recipient's last-login bot. Empty falls back to the recipient's service
-	// language at the gateway.
-	Language      string `protobuf:"bytes,5,opt,name=language,proto3" json:"language,omitempty"`
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	UserId        string                 `protobuf:"bytes,1,opt,name=user_id,json=userId,proto3" json:"user_id,omitempty"`
+	Kind          string                 `protobuf:"bytes,2,opt,name=kind,proto3" json:"kind,omitempty"`
+	Payload       []byte                 `protobuf:"bytes,3,opt,name=payload,proto3" json:"payload,omitempty"`
+	EventId       string                 `protobuf:"bytes,4,opt,name=event_id,json=eventId,proto3" json:"event_id,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -151,13 +146,6 @@ func (x *Event) GetEventId() string {
 	return ""
 }
 
-func (x *Event) GetLanguage() string {
-	if x != nil {
-		return x.Language
-	}
-	return ""
-}
-
 var File_push_v1_push_proto protoreflect.FileDescriptor
 
 const file_push_v1_push_proto_rawDesc = "" +
@@ -165,13 +153,12 @@ const file_push_v1_push_proto_rawDesc = "" +
 	"\x12push/v1/push.proto\x12\x10scrabble.push.v1\"1\n" +
 	"\x10SubscribeRequest\x12\x1d\n" +
 	"\n" +
-	"gateway_id\x18\x01 \x01(\tR\tgatewayId\"\x85\x01\n" +
+	"gateway_id\x18\x01 \x01(\tR\tgatewayId\"i\n" +
 	"\x05Event\x12\x17\n" +
 	"\auser_id\x18\x01 \x01(\tR\x06userId\x12\x12\n" +
 	"\x04kind\x18\x02 \x01(\tR\x04kind\x12\x18\n" +
 	"\apayload\x18\x03 \x01(\fR\apayload\x12\x19\n" +
-	"\bevent_id\x18\x04 \x01(\tR\aeventId\x12\x1a\n" +
-	"\blanguage\x18\x05 \x01(\tR\blanguage2R\n" +
+	"\bevent_id\x18\x04 \x01(\tR\aeventId2R\n" +
 	"\x04Push\x12J\n" +
 	"\tSubscribe\x12\".scrabble.push.v1.SubscribeRequest\x1a\x17.scrabble.push.v1.Event0\x01B#Z!scrabble/pkg/proto/push/v1;pushv1b\x06proto3"
 

pkg/proto/push/v1/push.proto

@@ -33,9 +33,4 @@ message Event {
   string kind = 2;
   bytes payload = 3;
   string event_id = 4;
-  // language routes an out-of-app push to a specific per-language bot: for a game
-  // event it carries the game's language ("en"/"ru") so the notification comes from the game's
-  // bot rather than the recipient's last-login bot. Empty falls back to the recipient's service
-  // language at the gateway.
-  string language = 5;
 }

pkg/proto/telegram/v1/telegram.pb.go

@@ -79,22 +79,15 @@ func (x *ValidateInitDataRequest) GetInitData() string {
 
 // ValidateInitDataResponse is the validated identity. external_id is the Telegram
 // user id used as the identities external_id; language_code seeds a new account's
-// preferred (interface) language. service_language (en/ru) is the language tag of
-// the bot that validated the launch data; it is persisted per account and routes
-// the user's out-of-app push back through the right bot (it is NOT the game's
-// language). supported_languages is that bot's set of offered game languages
-// (subset of {en, ru}, at least one — a singleton for a single-language bot); the
-// UI gates the New Game variant choice by it.
+// preferred (interface) language.
 type ValidateInitDataResponse struct {
-	state              protoimpl.MessageState `protogen:"open.v1"`
-	ExternalId         string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
-	Username           string                 `protobuf:"bytes,2,opt,name=username,proto3" json:"username,omitempty"`
-	FirstName          string                 `protobuf:"bytes,3,opt,name=first_name,json=firstName,proto3" json:"first_name,omitempty"`
-	LanguageCode       string                 `protobuf:"bytes,4,opt,name=language_code,json=languageCode,proto3" json:"language_code,omitempty"`
-	ServiceLanguage    string                 `protobuf:"bytes,5,opt,name=service_language,json=serviceLanguage,proto3" json:"service_language,omitempty"`
-	SupportedLanguages []string               `protobuf:"bytes,6,rep,name=supported_languages,json=supportedLanguages,proto3" json:"supported_languages,omitempty"`
-	unknownFields      protoimpl.UnknownFields
-	sizeCache          protoimpl.SizeCache
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	ExternalId    string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
+	Username      string                 `protobuf:"bytes,2,opt,name=username,proto3" json:"username,omitempty"`
+	FirstName     string                 `protobuf:"bytes,3,opt,name=first_name,json=firstName,proto3" json:"first_name,omitempty"`
+	LanguageCode  string                 `protobuf:"bytes,4,opt,name=language_code,json=languageCode,proto3" json:"language_code,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *ValidateInitDataResponse) Reset() {
@@ -155,20 +148,6 @@ func (x *ValidateInitDataResponse) GetLanguageCode() string {
 	return ""
 }
 
-func (x *ValidateInitDataResponse) GetServiceLanguage() string {
-	if x != nil {
-		return x.ServiceLanguage
-	}
-	return ""
-}
-
-func (x *ValidateInitDataResponse) GetSupportedLanguages() []string {
-	if x != nil {
-		return x.SupportedLanguages
-	}
-	return nil
-}
-
 // ValidateLoginWidgetRequest carries the Login Widget result serialized as a URL
 // query string (the widget fields plus the hash, e.g. "auth_date=...&id=...&hash=...").
 type ValidateLoginWidgetRequest struct {
@@ -280,9 +259,8 @@ func (x *ValidateLoginWidgetResponse) GetFirstName() string {
 
 // NotifyRequest addresses a push event to one recipient. kind is the backend push
 // catalog kind (your_turn, nudge, match_found, notify); payload is the FlatBuffers
-// scrabblefb.* body for that kind; language (en/ru) is the recipient's service
-// language (from their last ValidateInitData) — it both selects the delivering bot
-// and the message template.
+// scrabblefb.* body for that kind; language (en/ru) is the recipient's interface
+// language, used to render the message template (the single bot needs no routing).
 type NotifyRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	ExternalId    string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
@@ -397,14 +375,11 @@ func (x *NotifyResponse) GetDelivered() bool {
 	return false
 }
 
-// SendToUserRequest is an admin text message to one user by external_id. language
-// (en/ru) selects which bot delivers it — an operator choice in the admin console,
-// unrelated to the user's service language.
+// SendToUserRequest is an admin text message to one user by external_id.
 type SendToUserRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	ExternalId    string                 `protobuf:"bytes,1,opt,name=external_id,json=externalId,proto3" json:"external_id,omitempty"`
 	Text          string                 `protobuf:"bytes,2,opt,name=text,proto3" json:"text,omitempty"`
-	Language      string                 `protobuf:"bytes,3,opt,name=language,proto3" json:"language,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -453,20 +428,10 @@ func (x *SendToUserRequest) GetText() string {
 	return ""
 }
 
-func (x *SendToUserRequest) GetLanguage() string {
-	if x != nil {
-		return x.Language
-	}
-	return ""
-}
-
-// SendToGameChannelRequest is an admin text message to a game channel. language
-// (en/ru) selects which bot's configured channel receives it — an operator choice
-// in the admin console.
+// SendToGameChannelRequest is an admin text message to the bot's game channel.
 type SendToGameChannelRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	Text          string                 `protobuf:"bytes,1,opt,name=text,proto3" json:"text,omitempty"`
-	Language      string                 `protobuf:"bytes,2,opt,name=language,proto3" json:"language,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -508,13 +473,6 @@ func (x *SendToGameChannelRequest) GetText() string {
 	return ""
 }
 
-func (x *SendToGameChannelRequest) GetLanguage() string {
-	if x != nil {
-		return x.Language
-	}
-	return ""
-}
-
 // SendResponse reports whether the message was sent.
 type SendResponse struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
@@ -566,16 +524,14 @@ const file_telegram_v1_telegram_proto_rawDesc = "" +
 	"\n" +
 	"\x1atelegram/v1/telegram.proto\x12\x14scrabble.telegram.v1\"6\n" +
 	"\x17ValidateInitDataRequest\x12\x1b\n" +
-	"\tinit_data\x18\x01 \x01(\tR\binitData\"\xf7\x01\n" +
+	"\tinit_data\x18\x01 \x01(\tR\binitData\"\x9b\x01\n" +
 	"\x18ValidateInitDataResponse\x12\x1f\n" +
 	"\vexternal_id\x18\x01 \x01(\tR\n" +
 	"externalId\x12\x1a\n" +
 	"\busername\x18\x02 \x01(\tR\busername\x12\x1d\n" +
 	"\n" +
 	"first_name\x18\x03 \x01(\tR\tfirstName\x12#\n" +
-	"\rlanguage_code\x18\x04 \x01(\tR\flanguageCode\x12)\n" +
-	"\x10service_language\x18\x05 \x01(\tR\x0fserviceLanguage\x12/\n" +
-	"\x13supported_languages\x18\x06 \x03(\tR\x12supportedLanguages\"0\n" +
+	"\rlanguage_code\x18\x04 \x01(\tR\flanguageCode\"0\n" +
 	"\x1aValidateLoginWidgetRequest\x12\x12\n" +
 	"\x04data\x18\x01 \x01(\tR\x04data\"y\n" +
 	"\x1bValidateLoginWidgetResponse\x12\x1f\n" +
@@ -591,15 +547,13 @@ const file_telegram_v1_telegram_proto_rawDesc = "" +
 	"\apayload\x18\x03 \x01(\fR\apayload\x12\x1a\n" +
 	"\blanguage\x18\x04 \x01(\tR\blanguage\".\n" +
 	"\x0eNotifyResponse\x12\x1c\n" +
-	"\tdelivered\x18\x01 \x01(\bR\tdelivered\"d\n" +
+	"\tdelivered\x18\x01 \x01(\bR\tdelivered\"H\n" +
 	"\x11SendToUserRequest\x12\x1f\n" +
 	"\vexternal_id\x18\x01 \x01(\tR\n" +
 	"externalId\x12\x12\n" +
-	"\x04text\x18\x02 \x01(\tR\x04text\x12\x1a\n" +
-	"\blanguage\x18\x03 \x01(\tR\blanguage\"J\n" +
+	"\x04text\x18\x02 \x01(\tR\x04text\".\n" +
 	"\x18SendToGameChannelRequest\x12\x12\n" +
-	"\x04text\x18\x01 \x01(\tR\x04text\x12\x1a\n" +
-	"\blanguage\x18\x02 \x01(\tR\blanguage\",\n" +
+	"\x04text\x18\x01 \x01(\tR\x04text\",\n" +
 	"\fSendResponse\x12\x1c\n" +
 	"\tdelivered\x18\x01 \x01(\bR\tdelivered2\x92\x04\n" +
 	"\bTelegram\x12q\n" +

pkg/proto/telegram/v1/telegram.proto

@@ -31,13 +31,11 @@ service Telegram {
   // localized message with a Mini App deep-link button from the FlatBuffers
   // payload; unrenderable kinds are skipped (delivered=false).
   rpc Notify(NotifyRequest) returns (NotifyResponse);
-  // SendToUser sends an arbitrary text message to one user through the bot the
-  // request selects by language (admin use). delivered is false
-  // when the user has not started that bot.
+  // SendToUser sends an arbitrary text message to one user (admin use). delivered is
+  // false when the user has not started the bot.
   rpc SendToUser(SendToUserRequest) returns (SendResponse);
-  // SendToGameChannel posts an arbitrary text message to the game channel of the
-  // bot the request selects by language (admin use); the channel
-  // ids live only in the connector configuration.
+  // SendToGameChannel posts an arbitrary text message to the bot's game channel
+  // (admin use); the channel id lives only in the connector configuration.
   rpc SendToGameChannel(SendToGameChannelRequest) returns (SendResponse);
 }
 
@@ -48,19 +46,12 @@ message ValidateInitDataRequest {
 
 // ValidateInitDataResponse is the validated identity. external_id is the Telegram
 // user id used as the identities external_id; language_code seeds a new account's
-// preferred (interface) language. service_language (en/ru) is the language tag of
-// the bot that validated the launch data; it is persisted per account and routes
-// the user's out-of-app push back through the right bot (it is NOT the game's
-// language). supported_languages is that bot's set of offered game languages
-// (subset of {en, ru}, at least one — a singleton for a single-language bot); the
-// UI gates the New Game variant choice by it.
+// preferred (interface) language.
 message ValidateInitDataResponse {
   string external_id = 1;
   string username = 2;
   string first_name = 3;
   string language_code = 4;
-  string service_language = 5;
-  repeated string supported_languages = 6;
 }
 
 // ValidateLoginWidgetRequest carries the Login Widget result serialized as a URL
@@ -80,9 +71,8 @@ message ValidateLoginWidgetResponse {
 
 // NotifyRequest addresses a push event to one recipient. kind is the backend push
 // catalog kind (your_turn, nudge, match_found, notify); payload is the FlatBuffers
-// scrabblefb.* body for that kind; language (en/ru) is the recipient's service
-// language (from their last ValidateInitData) — it both selects the delivering bot
-// and the message template.
+// scrabblefb.* body for that kind; language (en/ru) is the recipient's interface
+// language, used to render the message template (the single bot needs no routing).
 message NotifyRequest {
   string external_id = 1;
   string kind = 2;
@@ -96,21 +86,15 @@ message NotifyResponse {
   bool delivered = 1;
 }
 
-// SendToUserRequest is an admin text message to one user by external_id. language
-// (en/ru) selects which bot delivers it — an operator choice in the admin console,
-// unrelated to the user's service language.
+// SendToUserRequest is an admin text message to one user by external_id.
 message SendToUserRequest {
   string external_id = 1;
   string text = 2;
-  string language = 3;
 }
 
-// SendToGameChannelRequest is an admin text message to a game channel. language
-// (en/ru) selects which bot's configured channel receives it — an operator choice
-// in the admin console.
+// SendToGameChannelRequest is an admin text message to the bot's game channel.
 message SendToGameChannelRequest {
   string text = 1;
-  string language = 2;
 }
 
 // SendResponse reports whether the message was sent.

pkg/proto/telegram/v1/telegram_grpc.pb.go

@@ -58,13 +58,11 @@ type TelegramClient interface {
 	// localized message with a Mini App deep-link button from the FlatBuffers
 	// payload; unrenderable kinds are skipped (delivered=false).
 	Notify(ctx context.Context, in *NotifyRequest, opts ...grpc.CallOption) (*NotifyResponse, error)
-	// SendToUser sends an arbitrary text message to one user through the bot the
-	// request selects by language (admin use). delivered is false
-	// when the user has not started that bot.
+	// SendToUser sends an arbitrary text message to one user (admin use). delivered is
+	// false when the user has not started the bot.
 	SendToUser(ctx context.Context, in *SendToUserRequest, opts ...grpc.CallOption) (*SendResponse, error)
-	// SendToGameChannel posts an arbitrary text message to the game channel of the
-	// bot the request selects by language (admin use); the channel
-	// ids live only in the connector configuration.
+	// SendToGameChannel posts an arbitrary text message to the bot's game channel
+	// (admin use); the channel id lives only in the connector configuration.
 	SendToGameChannel(ctx context.Context, in *SendToGameChannelRequest, opts ...grpc.CallOption) (*SendResponse, error)
 }
 
@@ -147,13 +145,11 @@ type TelegramServer interface {
 	// localized message with a Mini App deep-link button from the FlatBuffers
 	// payload; unrenderable kinds are skipped (delivered=false).
 	Notify(context.Context, *NotifyRequest) (*NotifyResponse, error)
-	// SendToUser sends an arbitrary text message to one user through the bot the
-	// request selects by language (admin use). delivered is false
-	// when the user has not started that bot.
+	// SendToUser sends an arbitrary text message to one user (admin use). delivered is
+	// false when the user has not started the bot.
 	SendToUser(context.Context, *SendToUserRequest) (*SendResponse, error)
-	// SendToGameChannel posts an arbitrary text message to the game channel of the
-	// bot the request selects by language (admin use); the channel
-	// ids live only in the connector configuration.
+	// SendToGameChannel posts an arbitrary text message to the bot's game channel
+	// (admin use); the channel id lives only in the connector configuration.
 	SendToGameChannel(context.Context, *SendToGameChannelRequest) (*SendResponse, error)
 	mustEmbedUnimplementedTelegramServer()
 }