Is federal habeas review barred under Martinez v. Ryan, 566 U.S. 1 (2012) and a claim procedurally defaulted when a petitioner fails to bring an independent constitutional claim based on ineffective assistance of counsel when the state failed to appoint counsel in an initial-review state collateral proceeding?

Whether the prosecutor's statements shifting the burden of proof to the defendant during closing arguments constituted prejudicial misconduct under Darden v. Wainwright