Complete authentication and profile features

backend/app/services/link_service.py

@@ -55,3 +55,11 @@ def list_public_links(username: str | None = None):
             (username, username),
         ).fetchall()
     return [dict(row) for row in rows]
+
+
+def list_public_users():
+    with get_connection() as conn:
+        rows = conn.execute(
+            'SELECT username FROM users ORDER BY username'
+        ).fetchall()
+    return [row['username'] for row in rows]