feat: add NFT usernames and bot verification (#22)

Implements collectible usernames, official verification workflows, and third-party bot verification after maintainer protocol and migration review.

The composite activity/moderation rating remains an admin-only read model; Telegram Stars Rating wire fields stay unset pending a dedicated official-semantics implementation.

Reviewed-Head: 2796345775ea0f908fb7734601e5e1dee4b653b9
Original-Head: fa082b892fd5180c9c9bc53c81c21cf5d250a75b

Co-authored-by: Egor Egorov <business.egor.sg@gmail.com>

internal/rpc/username_notify_test.go

@@ -0,0 +1,94 @@
+package rpc
+
+import (
+	"context"
+	"testing"
+
+	"github.com/iamxvbaba/td/clock"
+	"github.com/iamxvbaba/td/tg"
+	"go.uber.org/zap"
+
+	usernamesapp "telesrv/internal/app/usernames"
+	"telesrv/internal/domain"
+)
+
+var _ usernamesapp.PeerUsernameNotifier = (*Router)(nil)
+
+func TestNotifyPeerUsernamesChangedUserPushesPreloadedVector(t *testing.T) {
+	const (
+		targetID = int64(2002)
+		viewerID = int64(1001)
+	)
+	users := &verifiedNotifyUsers{
+		user:     domain.User{ID: targetID, FirstName: "Owner", Username: "owner_slot"},
+		found:    true,
+		audience: []int64{targetID, viewerID},
+	}
+	registry := newFakeUsernameRegistry()
+	registry.byPeer[domain.Peer{Type: domain.PeerTypeUser, ID: targetID}] = []domain.Username{
+		{Username: "owner_slot", Editable: true, Active: true},
+		{Username: "nft", Active: true, CollectibleID: 7},
+	}
+	sessions := &captureSessions{onlineUserIDs: []int64{targetID, viewerID}}
+	r := New(Config{}, Deps{Users: users, Usernames: registry, Sessions: sessions}, zap.NewNop(), clock.System)
+
+	if err := r.NotifyPeerUsernamesChanged(context.Background(), domain.Peer{
+		Type: domain.PeerTypeUser, ID: targetID,
+	}); err != nil {
+		t.Fatalf("notify user usernames: %v", err)
+	}
+	if registry.peerCalls != 1 || registry.batchCalls != 0 {
+		t.Fatalf("registry reads = peer %d / batch %d, want one peer-wide read", registry.peerCalls, registry.batchCalls)
+	}
+	updates := sessions.lastUserPush().(*tg.Updates)
+	user := updates.Users[0].(*tg.User)
+	if scalar, ok := user.GetUsername(); ok || scalar != "" {
+		t.Fatalf("pushed scalar username = %q (set %v), want absent", scalar, ok)
+	}
+	vector, ok := user.GetUsernames()
+	if !ok || len(vector) != 2 || vector[1].Username != "nft" {
+		t.Fatalf("pushed username vector = %+v (set %v)", vector, ok)
+	}
+}
+
+func TestNotifyPeerUsernamesChangedChannelPushesPreloadedVector(t *testing.T) {
+	const (
+		channelID = int64(4004)
+		ownerID   = int64(3003)
+		memberID  = int64(3004)
+	)
+	channels := &verifiedNotifyChannels{channel: domain.Channel{
+		ID: channelID, AccessHash: 44, CreatorUserID: ownerID,
+		Title: "Collectible", Username: "channel_slot", Broadcast: true,
+	}}
+	registry := newFakeUsernameRegistry()
+	registry.byPeer[domain.Peer{Type: domain.PeerTypeChannel, ID: channelID}] = []domain.Username{
+		{Username: "channel_slot", Editable: true, Active: true},
+		{Username: "collectible", Active: true, CollectibleID: 9},
+	}
+	sessions := &captureSessions{
+		onlineUserIDs:  []int64{ownerID, memberID},
+		channelMembers: map[int64][]int64{channelID: {ownerID, memberID}},
+	}
+	r := New(Config{}, Deps{
+		Channels: channels, Usernames: registry, Sessions: sessions,
+	}, zap.NewNop(), clock.System)
+
+	if err := r.NotifyPeerUsernamesChanged(context.Background(), domain.Peer{
+		Type: domain.PeerTypeChannel, ID: channelID,
+	}); err != nil {
+		t.Fatalf("notify channel usernames: %v", err)
+	}
+	if registry.peerCalls != 1 || registry.batchCalls != 0 {
+		t.Fatalf("registry reads = peer %d / batch %d, want one peer-wide read", registry.peerCalls, registry.batchCalls)
+	}
+	updates := sessions.lastUserPush().(*tg.Updates)
+	channel := updates.Chats[0].(*tg.Channel)
+	if scalar, ok := channel.GetUsername(); ok || scalar != "" {
+		t.Fatalf("pushed scalar username = %q (set %v), want absent", scalar, ok)
+	}
+	vector, ok := channel.GetUsernames()
+	if !ok || len(vector) != 2 || vector[1].Username != "collectible" {
+		t.Fatalf("pushed username vector = %+v (set %v)", vector, ok)
+	}
+}