[ad_1] Columbia University awoke Wednesday after it narrowly avoided, for now, another confrontation with students over their sprawling protest encampment. But the university faced a swirl of doubts over the future of its president, Nemat Shafik, and her efforts to calm the campus in Upper Manhattan. Underscoring the spectrum of pressures on Dr. Shafik, the columbia campus was bracing for a day of studied tumult, with House Speaker Mike Johnson scheduled to visit Jewish students at Columbia and Dr. Shafik expected to confer with the university senate, which could censure…