Non-blocking sampling reads process memory while the target continuesrunning, which can produce torn stacks when generators or coroutinesrapidly switch between yield points. Blocking mode uses atomic processsuspension (task_suspend on macOS, NtSuspendProcess on Windows,PTRACE_SEIZE on Linux) to stop the target during each sample, ensuringconsistent snapshots.Use blocking mode with longer intervals (1ms+) to avoid impacting thetarget too much. The default non-blocking mode remains best for mostcases since it has zero overhead.Also fix a frame cache bug: the cache was including the last_profiled_frameitself when extending with cached data, but this frame was executing inthe previous sample and its line number may have changed. For example,if function A was sampled at line 6, then execution continued to line 10and called B→C, the next sample would incorrectly report A at line 6(from cache) instead of line 10. The fix uses start_idx + 1 to only trustframes ABOVE last_profiled_frame — these caller frames are frozen at theircall sites and cannot change until their callees return.Signed-off-by: Pablo Galindo <pablogsal@gmail.com>