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.

platform/telegram/internal/deeplink/deeplink.go

@@ -0,0 +1,56 @@
+// Package deeplink builds and parses the Telegram Mini App "start parameters" that
+// route a launch to a specific destination. The scheme is shared verbatim with the
+// UI (ui/src/lib/deeplink.ts): a one-character kind prefix followed by a value —
+//
+//	g<game uuid>        open that game
+//	i<invitation uuid>  open that invitation
+//	f<6-digit code>     redeem that friend code
+//
+// An empty or unrecognised parameter opens the lobby. UUIDs keep their dashes,
+// which are allowed in a Telegram startapp parameter ([A-Za-z0-9_-]).
+package deeplink
+
+import "strings"
+
+// Kind prefixes for the start-parameter scheme.
+const (
+	prefixGame       = "g"
+	prefixInvitation = "i"
+	prefixFriendCode = "f"
+)
+
+// Kind classifies a start parameter.
+type Kind int
+
+// The start-parameter kinds.
+const (
+	KindLobby Kind = iota
+	KindGame
+	KindInvitation
+	KindFriendCode
+)
+
+// Game returns the start parameter that opens the game with the given id.
+func Game(id string) string { return prefixGame + id }
+
+// Invitation returns the start parameter that opens the invitation with the id.
+func Invitation(id string) string { return prefixInvitation + id }
+
+// FriendCode returns the start parameter that redeems the given friend code.
+func FriendCode(code string) string { return prefixFriendCode + code }
+
+// Parse classifies a start parameter and returns its value (the part after the
+// kind prefix). An empty or unrecognised parameter is KindLobby with an empty
+// value.
+func Parse(p string) (Kind, string) {
+	switch {
+	case strings.HasPrefix(p, prefixGame):
+		return KindGame, p[len(prefixGame):]
+	case strings.HasPrefix(p, prefixInvitation):
+		return KindInvitation, p[len(prefixInvitation):]
+	case strings.HasPrefix(p, prefixFriendCode):
+		return KindFriendCode, p[len(prefixFriendCode):]
+	default:
+		return KindLobby, ""
+	}
+}

platform/telegram/internal/deeplink/deeplink_test.go

@@ -0,0 +1,41 @@
+package deeplink
+
+import "testing"
+
+func TestBuildAndParse(t *testing.T) {
+	cases := []struct {
+		name      string
+		param     string
+		wantKind  Kind
+		wantValue string
+	}{
+		{"game", Game("7c9e6679-7425-40de-944b-e07fc1f90ae7"), KindGame, "7c9e6679-7425-40de-944b-e07fc1f90ae7"},
+		{"invitation", Invitation("11111111-2222-3333-4444-555555555555"), KindInvitation, "11111111-2222-3333-4444-555555555555"},
+		{"friend code", FriendCode("123456"), KindFriendCode, "123456"},
+		{"empty is lobby", "", KindLobby, ""},
+		{"unknown is lobby", "x-nope", KindLobby, ""},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			gotKind, gotValue := Parse(tc.param)
+			if gotKind != tc.wantKind {
+				t.Errorf("kind = %d, want %d", gotKind, tc.wantKind)
+			}
+			if gotValue != tc.wantValue {
+				t.Errorf("value = %q, want %q", gotValue, tc.wantValue)
+			}
+		})
+	}
+}
+
+func TestBuildPrefixes(t *testing.T) {
+	if Game("x") != "gx" {
+		t.Errorf("Game = %q, want gx", Game("x"))
+	}
+	if Invitation("x") != "ix" {
+		t.Errorf("Invitation = %q, want ix", Invitation("x"))
+	}
+	if FriendCode("123456") != "f123456" {
+		t.Errorf("FriendCode = %q, want f123456", FriendCode("123456"))
+	}
+}