OAKLAND — Paul Tamm, a civic leader who served as mayor and helped start a cycling program for at-risk youth, died Saturday of complications from prostate cancer. He was 68. “He really believed in community and that the whole is stronger than the parts,” his widow, Betty Tamm, said today. “When people worked together, you can get a lot done.” The Tamms moved to Oakland from Oakland, Calif., in 1991 to escape the bustle of the big city. Paul Tamm enjoyed the community aspect of the smaller Oakland and pursued his passion for outdoor activities such as cycling, hiking and …