Millimeter-wave (mmWave) radar offers significant potential for fine-grained sensing, yet transitioning from controlled laboratory environments to dynamic real-world applications remains challenging. Existing methods face a dichotomy: real-time point clouds sacrifice crucial signal details needed for sophisticated tasks, whereas information-rich raw data sensing imposes prohibitive transmission and computation overheads, often limiting analysis to offline settings and hindering real-time viability. To this end, we present CoSense, areal-timeedge-end collaborative sensing system built on commodity mmWave radar (end) and edge intelligence. We first introduce a novel dual-stream data acquisition mechanism via realizing radar driver-level interfaces, enabling simultaneous transmission of point clouds and raw data. To bridge the fidelity-latency trade-off, we implement an adaptive transmission strategy via firmware modifications, selectively forwarding raw data segments (corresponding to regions of interest identified in the point cloud) for detailed fine-grained analysis, while continuously delivering point clouds for low-latency coarse-grained sensing and control loops. Furthermore, we incorporate closed-loop feedback beamforming, dynamically steering the radar beam based on real-time tracking to counteract motion-induced misalignment and enhance signal fidelity. Extensive evaluations under dynamic conditions demonstrate that CoSense successfully achieves real-time fine-grained sensing with high fidelity and manageable overhead.