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.

pkg/fbs/scrabblefb/Profile.go

@@ -137,8 +137,20 @@ func (rcv *Profile) AwayEnd() []byte {
 	return nil
 }
 
+func (rcv *Profile) NotificationsInAppOnly() bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(24))
+	if o != 0 {
+		return rcv._tab.GetBool(o + rcv._tab.Pos)
+	}
+	return true
+}
+
+func (rcv *Profile) MutateNotificationsInAppOnly(n bool) bool {
+	return rcv._tab.MutateBoolSlot(24, n)
+}
+
 func ProfileStart(builder *flatbuffers.Builder) {
-	builder.StartObject(10)
+	builder.StartObject(11)
 }
 func ProfileAddUserId(builder *flatbuffers.Builder, userId flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(userId), 0)
@@ -170,6 +182,9 @@ func ProfileAddAwayStart(builder *flatbuffers.Builder, awayStart flatbuffers.UOf
 func ProfileAddAwayEnd(builder *flatbuffers.Builder, awayEnd flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(9, flatbuffers.UOffsetT(awayEnd), 0)
 }
+func ProfileAddNotificationsInAppOnly(builder *flatbuffers.Builder, notificationsInAppOnly bool) {
+	builder.PrependBoolSlot(10, notificationsInAppOnly, true)
+}
 func ProfileEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }