fix launchable notebook api_settings: dict -> ApiSettings(...) pydantic model

cuOpt 26.4 + pydantic settings migration in PR #32 requires ApiSettings
instead of plain dicts. Two cells in launchable.ipynb still passed dicts,
causing AttributeError: 'dict' object has no attribute 'api' at runtime.

Author: jgoldberg-nvidia

notebooks/launchable.ipynb

@@ -2073,20 +2073,20 @@
    ],
    "source": [
     "# Instantiate CVaR optimization problem for the S&P 500 example\n",
-    "api_settings = {\n",
-    "                \"api\": \"cvxpy\",  # \"cvxpy\" or \"cuopt_python\"\n",
-    "                \"weight_constraints_type\": \"parameter\",  # \"parameter\" or \"bounds\" (CVXPY only)\n",
-    "                \"cash_constraints_type\": \"parameter\",  # \"parameter\" or \"bounds\" (CVXPY only)\n",
-    "            }\n",
+    "api_settings = ApiSettings(\n",
+    "    api=\"cvxpy\",  # \"cvxpy\" or \"cuopt_python\"\n",
+    "    weight_constraints_type=\"parameter\",  # \"parameter\" or \"bounds\" (CVXPY only)\n",
+    "    cash_constraints_type=\"parameter\",  # \"parameter\" or \"bounds\" (CVXPY only)\n",
+    ")\n",
     "cvar_problem = cvar_optimizer.CVaR(\n",
     "    returns_dict=returns_dict,\n",
     "    cvar_params=cvar_params,\n",
     "    api_settings=api_settings\n",
     ")\n",
     "\n",
     "# Solve on GPU\n",
-    "gpu_solver_settings = {\"solver\":cp.CUOPT, \"verbose\": False, \"solver_method\": \"PDLP\"} \n",
-    "gpu_results, gpu_portfolio = cvar_problem.solve_optimization_problem(solver_settings=gpu_solver_settings)\n"
+    "gpu_solver_settings = {\"solver\": cp.CUOPT, \"verbose\": False, \"solver_method\": \"PDLP\"}\n",
+    "gpu_results, gpu_portfolio = cvar_problem.solve_optimization_problem(solver_settings=gpu_solver_settings)"
    ]
   },
   {
@@ -2221,14 +2221,14 @@
     "cvar_problem = cvar_optimizer.CVaR(\n",
     "    returns_dict=returns_dict,\n",
     "    cvar_params=cvar_params,\n",
-    "    api_settings={\"api\": \"cuopt_python\"}\n",
+    "    api_settings=ApiSettings(api=\"cuopt_python\")\n",
     ")\n",
     "\n",
     "# Solver settings for cuOpt Python API\n",
-    "cuopt_settings = {\"log_to_console\":True, \"presolve\": 0, \"method\": 1}\n",
+    "cuopt_settings = {\"log_to_console\": True, \"presolve\": 0, \"method\": 1}\n",
     "\n",
     "# Solve using cuOpt Python API\n",
-    "cuopt_gpu_results, cuopt_gpu_portfolio = cvar_problem.solve_optimization_problem(solver_settings=cuopt_settings)\n"
+    "cuopt_gpu_results, cuopt_gpu_portfolio = cvar_problem.solve_optimization_problem(solver_settings=cuopt_settings)"
    ]
   },
   {