EDWARD MCALLISTER and MAHAMAT RAMADANE CHAD's capital N'Djamena was rocked by violent protests this morning as demonstrators took to the streets demanding a return to civilian rule after the military took control following President Idriss Deby's battlefield death last week. The unrest underscores the tense atmosphere in Chad following Deby's death, where the military transition is already struggling to win over a population exhausted by 30 years of monolithic rule. The military council seized power after Deby was killed as he visited troops fighting rebels on April 19. Some opposition politicians have called the military takeover a coup and asked…