Stage 9: Telegram integration (connector side-service, Mini App, out-of-app push)

New platform/telegram connector (own container, bot token only there):
- go-telegram/bot long-poll loop: /start deep-links + Mini App launch button.
- gRPC API pkg/proto/telegram/v1 (Telegram service): ValidateInitData, Notify
  (renders a localized message + deep-link button), SendToUser/SendToGameChannel
  (admin, wired in Stage 10). Generic methods are platform-agnostic (external_id).
- Bot API base override for Telegram's test environment; Dockerfile + compose
  (VPN sidecar, no public ingress); README.

Gateway:
- initData validation relocated from the gateway into the connector; the gateway
  calls ValidateInitData over gRPC (GATEWAY_CONNECTOR_ADDR), drops the bot token,
  and deletes internal/auth.
- Out-of-app push: runPushPump routes events whose recipient has no live in-app
  stream to connector.Notify, gated by /internal/push-target + the in-app-only
  flag (race-free de-dup); HasSubscribers added to the push hub.

Backend:
- Migration 00007 accounts.notifications_in_app_only (default true) + jetgen.
- ProvisionTelegram seeds a new account's language/display name from the launch
  fields; IdentityExternalID reverse lookup; /internal/push-target handler.

UI:
- Telegram Mini App launch: detect initData, apply themeParams, authTelegram,
  route the deep-link start_param (g/i/f); /telegram/ guard redirects outside
  Telegram. Vite relative base + telegram-web-app.js. In-app-only profile toggle;
  share-to-Telegram link for a friend code. Vitest + Playwright coverage.

Wire/docs/CI: fbs Profile/UpdateProfileRequest gain notifications_in_app_only
(Go + TS); go.work uses ./platform/telegram; go-unit.yaml covers it; PLAN,
ARCHITECTURE, FUNCTIONAL (+ru), UI_DESIGN, READMEs updated.

gateway/internal/backendclient/api.go

@@ -20,16 +20,17 @@ type SessionResp struct {
 
 // ProfileResp is an account's own profile.
 type ProfileResp struct {
-	UserID              string `json:"user_id"`
-	DisplayName         string `json:"display_name"`
-	PreferredLanguage   string `json:"preferred_language"`
-	TimeZone            string `json:"time_zone"`
-	AwayStart           string `json:"away_start"`
-	AwayEnd             string `json:"away_end"`
-	HintBalance         int    `json:"hint_balance"`
-	BlockChat           bool   `json:"block_chat"`
-	BlockFriendRequests bool   `json:"block_friend_requests"`
-	IsGuest             bool   `json:"is_guest"`
+	UserID                 string `json:"user_id"`
+	DisplayName            string `json:"display_name"`
+	PreferredLanguage      string `json:"preferred_language"`
+	TimeZone               string `json:"time_zone"`
+	AwayStart              string `json:"away_start"`
+	AwayEnd                string `json:"away_end"`
+	HintBalance            int    `json:"hint_balance"`
+	BlockChat              bool   `json:"block_chat"`
+	BlockFriendRequests    bool   `json:"block_friend_requests"`
+	IsGuest                bool   `json:"is_guest"`
+	NotificationsInAppOnly bool   `json:"notifications_in_app_only"`
 }
 
 // TileJSON is one placed tile, used in both play requests and move responses.
@@ -109,11 +110,35 @@ type ChatResp struct {
 	CreatedAtUnix int64  `json:"created_at_unix"`
 }
 
-// TelegramAuth provisions/finds the Telegram account and mints a session.
-func (c *Client) TelegramAuth(ctx context.Context, externalID string) (SessionResp, error) {
+// TelegramAuth provisions/finds the Telegram account and mints a session, seeding a
+// brand-new account's display name and language from the validated launch fields.
+func (c *Client) TelegramAuth(ctx context.Context, externalID, languageCode, username, firstName string) (SessionResp, error) {
 	var out SessionResp
 	err := c.do(ctx, http.MethodPost, "/api/v1/internal/sessions/telegram", "", "",
-		map[string]string{"external_id": externalID}, &out)
+		map[string]string{
+			"external_id":   externalID,
+			"language_code": languageCode,
+			"username":      username,
+			"first_name":    firstName,
+		}, &out)
+	return out, err
+}
+
+// PushTargetResp is a recipient's out-of-app push routing data: their Telegram
+// external_id (empty when they have no Telegram identity), preferred language, and
+// whether they confined notifications to the in-app stream.
+type PushTargetResp struct {
+	ExternalID             string `json:"external_id"`
+	Language               string `json:"language"`
+	NotificationsInAppOnly bool   `json:"notifications_in_app_only"`
+}
+
+// PushTarget resolves a user id to their out-of-app Telegram routing data (the
+// gateway uses it to decide whether to deliver an event over platform push).
+func (c *Client) PushTarget(ctx context.Context, userID string) (PushTargetResp, error) {
+	var out PushTargetResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/push-target", "", "",
+		map[string]string{"user_id": userID}, &out)
 	return out, err
 }
 

gateway/internal/backendclient/api_social.go

@@ -215,13 +215,14 @@ func (c *Client) ListInvitations(ctx context.Context, userID string) (Invitation
 func (c *Client) UpdateProfile(ctx context.Context, userID string, p ProfileResp) (ProfileResp, error) {
 	var out ProfileResp
 	body := map[string]any{
-		"display_name":          p.DisplayName,
-		"preferred_language":    p.PreferredLanguage,
-		"time_zone":             p.TimeZone,
-		"away_start":            p.AwayStart,
-		"away_end":              p.AwayEnd,
-		"block_chat":            p.BlockChat,
-		"block_friend_requests": p.BlockFriendRequests,
+		"display_name":              p.DisplayName,
+		"preferred_language":        p.PreferredLanguage,
+		"time_zone":                 p.TimeZone,
+		"away_start":                p.AwayStart,
+		"away_end":                  p.AwayEnd,
+		"block_chat":                p.BlockChat,
+		"block_friend_requests":     p.BlockFriendRequests,
+		"notifications_in_app_only": p.NotificationsInAppOnly,
 	}
 	err := c.do(ctx, http.MethodPut, "/api/v1/user/profile", userID, "", body, &out)
 	return out, err