feat: disciple link

internal/repository/user_repo.go

@@ -37,7 +37,8 @@ const userColumns = `id, email, handle, password_hash, name, avatar_url, role, p
 	email_verified_at, token_version, created_at, updated_at, country,
 	sampradaya, gender, initiated, initiated_at, daily_chanting_rounds,
 	preferred_chanting_time, peak_active_time, banned_at,
-	bookmark_limit, public_collection_limit, private_collection_limit`
+	bookmark_limit, public_collection_limit, private_collection_limit,
+	disciple_id`
 
 // rowScanner is satisfied by both pgx.Row (QueryRow) and pgx.Rows, so
 // scanUser works for single-row and iterated reads alike.
@@ -53,6 +54,7 @@ func scanUser(row rowScanner, u *model.User) error {
 		&u.Sampradaya, &u.Gender, &u.Initiated, &u.InitiatedAt, &u.DailyChantingRounds,
 		&u.PreferredChantingTime, &u.PeakActiveTime, &u.BannedAt,
 		&u.BookmarkLimit, &u.PublicCollectionLimit, &u.PrivateCollectionLimit,
+		&u.DiscipleID,
 	)
 }
 
@@ -402,6 +404,41 @@ func (r *UserRepo) AllHandles(ctx context.Context) ([]string, error) {
 	return handles, rows.Err()
 }
 
+// DiscipleLink pairs a Mongo disciple id with the platform account an admin
+// has linked to it. Powers the /disciples browser highlight: the reader page
+// fetches the whole (small) set once and marks the matching cards.
+type DiscipleLink struct {
+	DiscipleID string  `json:"disciple_id"`
+	Handle     string  `json:"handle"`
+	Name       string  `json:"name"`
+	AvatarURL  *string `json:"avatar_url"`
+}
+
+// ListDiscipleLinks returns every user→disciple link. Deliberately unpaged:
+// only Śrīla Prabhupāda's own disciples are ever linked, so this is dozens of
+// rows at most and the partial index on disciple_id keeps it a cheap scan.
+// Suspended accounts are excluded so a banned user can't keep a public badge.
+func (r *UserRepo) ListDiscipleLinks(ctx context.Context) ([]DiscipleLink, error) {
+	rows, err := r.pg.Pool.Query(ctx, `
+		SELECT disciple_id, handle, name, avatar_url
+		FROM users
+		WHERE disciple_id IS NOT NULL AND banned_at IS NULL
+		ORDER BY name`)
+	if err != nil {
+		return nil, fmt.Errorf("list disciple links: %w", err)
+	}
+	defer rows.Close()
+	out := []DiscipleLink{}
+	for rows.Next() {
+		var l DiscipleLink
+		if err := rows.Scan(&l.DiscipleID, &l.Handle, &l.Name, &l.AvatarURL); err != nil {
+			return nil, fmt.Errorf("scan disciple link: %w", err)
+		}
+		out = append(out, l)
+	}
+	return out, rows.Err()
+}
+
 // RecentlyJoined returns up to `limit` users who registered on/after `since`,
 // newest first, as a discovery list for the feed's "new on the platform"
 // strip. Excludes the viewer, anyone the viewer already has a follow edge with