fix(metrics): strip units from GPU legend names; fix fan SDR parsing for new IPMI format

Legend names were "GPU 0 %" — remove unit suffix since chart title already
conveys it. Fan parsing now handles the 5-field IPMI SDR format where the
value+unit ("4340 RPM") are combined in the last column rather than split
across separate fields.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/webui/server.go

@@ -459,7 +459,7 @@ func (h *handler) handleMetricsChartSVG(w http.ResponseWriter, r *http.Request)
 			}
 			vUtil, l := gr.Util.snapshot()
 			datasets = append(datasets, vUtil)
-			names = append(names, fmt.Sprintf("GPU %d %%", idx))
+			names = append(names, fmt.Sprintf("GPU %d", idx))
 			if len(labels) == 0 {
 				labels = l
 			}
@@ -477,7 +477,7 @@ func (h *handler) handleMetricsChartSVG(w http.ResponseWriter, r *http.Request)
 			}
 			vMem, l := gr.MemUtil.snapshot()
 			datasets = append(datasets, vMem)
-			names = append(names, fmt.Sprintf("GPU %d %%", idx))
+			names = append(names, fmt.Sprintf("GPU %d", idx))
 			if len(labels) == 0 {
 				labels = l
 			}
@@ -495,7 +495,7 @@ func (h *handler) handleMetricsChartSVG(w http.ResponseWriter, r *http.Request)
 			}
 			vPow, l := gr.Power.snapshot()
 			datasets = append(datasets, vPow)
-			names = append(names, fmt.Sprintf("GPU %d W", idx))
+			names = append(names, fmt.Sprintf("GPU %d", idx))
 			if len(labels) == 0 {
 				labels = l
 			}
@@ -513,7 +513,7 @@ func (h *handler) handleMetricsChartSVG(w http.ResponseWriter, r *http.Request)
 			}
 			vTemp, l := gr.Temp.snapshot()
 			datasets = append(datasets, vTemp)
-			names = append(names, fmt.Sprintf("GPU %d °C", idx))
+			names = append(names, fmt.Sprintf("GPU %d", idx))
 			if len(labels) == 0 {
 				labels = l
 			}