A 52-year-old male farmer from rural Maharashtra undergoes elective open cholecystectomy for symptomatic cholelithiasis. The surgery is uncomplicated, and the wound is closed with interrupted silk sutures. On postoperative day 5, the patient develops fever (38.5°C), wound erythema, and purulent discharge. Wound culture grows Staphylococcus aureus. The surgical site infection is managed with antibiotics and local wound care. By postoperative day 21, the wound shows epithelialization but remains soft and friable with minimal tensile strength. Which phase of wound healing is predominantly affected in this patient?