A 45-year-old man from Madagascar presents with a 6-month history of chronic productive cough and constitutional symptoms. Sputum ZN stain shows AFB. GeneXpert is positive for M. tuberculosis with rifampicin resistance detected. Extended drug susceptibility testing confirms MDR-TB (resistance to isoniazid and rifampicin) but susceptibility to fluoroquinolones and aminoglycosides. According to WHO 2022 guidelines, what is the preferred shorter regimen?