Ensure telemetry events are flushed immediately (#1344)

The previous implementation used `flushIfNeeded` to batch most telemetry events, but it was not reliably sending them, leading to data loss. Notably, the `startSession` event, which already used `flushToClearcut`, was working correctly, indicating an issue with the batching logic itself.

This change replaces all calls to `flushIfNeeded` with `flushToClearcut` to align all event logging with the working `startSession` implementation and ensure that events are sent immediately. This prioritizes the reliability of data collection over network efficiency.

This is a temporary solution to prevent further data loss. The underlying issue with the batching mechanism in `flushIfNeeded` should be investigated and fixed in the future, at which point this change can be reverted.

packages/cli/src/ui/hooks/useToolScheduler.test.ts

@@ -49,6 +49,7 @@ const mockConfig = {
   getToolRegistry: vi.fn(() => mockToolRegistry as unknown as ToolRegistry),
   getApprovalMode: vi.fn(() => ApprovalMode.DEFAULT),
   getUsageStatisticsEnabled: () => true,
+  getDebugMode: () => false,
 };
 
 const mockTool: Tool = {