dsh-model-slider

DSH Web UI model seat: 3-level quick slider (low/medium/high, each preconfigured with model + reasoning effort), advanced model/effort picker, modality icons, and per-provider usage/balance display. DSH 模型选择器增强：低中高三档快切滑块 + 高级选择 + 模态图标 + 供应商用量显示。