Two weeks before Canada's most ambitious financial gathering in its history, the architect of its logistics has quietly stepped away. Laurel Broten, the chief executive who has spent years building the scaffolding for Prime Minister Carney's landmark investment summit, informed her staff this week that she is resigning — leaving the government to steady a high-stakes event designed to signal Canada's economic resilience at precisely the moment that resilience is being tested. In the long story of nations courting global capital, the departure of a key steward on the eve of the performance is a