feat: support GPU combinations on the GPU Graph action

com.bryce.llamawatch.sdPlugin/ui/gpu.html

@@ -14,6 +14,9 @@
     <sdpi-item label="GPU">
       <sdpi-select setting="gpuId" datasource="gpus" loading="Loading GPUs…" hot-reload default="all" placeholder="Select a GPU" />
     </sdpi-item>
+    <sdpi-item label="GPU combination">
+      <sdpi-textfield setting="gpuCombo" placeholder="e.g. 0,2 (overrides GPU)" />
+    </sdpi-item>
     <sdpi-item label="Metric">
       <sdpi-select setting="metric" default="util_percent" placeholder="Select a metric">
         <option value="util_percent">Utilization %</option>

src/actions/gpu-graph.ts

@@ -8,6 +8,7 @@ import streamDeck, {
   type WillDisappearEvent,
 } from "@elgato/streamdeck";
 import { type GpuMetricKind } from "../lib/metrics-parser";
+import { combineSeries } from "../lib/metrics-poller";
 import { renderGpuGraph, svgDataUrl } from "../lib/render";
 import { runtime } from "../lib/runtime";
 import { cfgFromSettings, type CfgSettings } from "../lib/util";
@@ -15,6 +16,7 @@ import { cfgFromSettings, type CfgSettings } from "../lib/util";
 type GpuSettings = CfgSettings & {
   gpuId?: string;
   metric?: GpuMetricKind;
+  gpuCombo?: string;
 };
 
 type GpuState = {
@@ -71,12 +73,28 @@ export class GpuGraph extends SingletonAction<GpuSettings> {
     const action = state.action;
     if (!action) return;
     const poller = runtime.pollerInstance;
-    const gpuId = state.settings.gpuId ?? "all";
     const metric = state.settings.metric ?? "util_percent";
-    const value = poller?.getValue(gpuId, metric);
-    const history = poller?.getHistory(gpuId, metric) ?? [];
+    const combo = parseCombo(state.settings.gpuCombo);
     const offline = !poller || poller.isOffline();
-    const gpuName = gpuId === "all" ? "ALL GPUS" : this.gpuLabel(gpuId);
+
+    let value: number | undefined;
+    let history: number[] = [];
+    let gpuName: string;
+    if (combo) {
+      const known = new Set((poller?.gpus() ?? []).map((g) => g.id));
+      const ids = combo.filter((id) => known.has(id));
+      const histories = ids.map((id) => poller?.getHistory(id, metric) ?? []);
+      const combined = combineSeries(histories, metric);
+      value = combined.value;
+      history = combined.history;
+      gpuName = `GPU ${ids.join("+")}`;
+    } else {
+      const gpuId = state.settings.gpuId ?? "all";
+      value = poller?.getValue(gpuId, metric);
+      history = poller?.getHistory(gpuId, metric) ?? [];
+      gpuName = gpuId === "all" ? "ALL GPUS" : this.gpuLabel(gpuId);
+    }
+
     const svg = renderGpuGraph({ gpuName, metric, value, history, offline });
     if (svg === state.lastSvg) return;
     state.lastSvg = svg;
@@ -88,3 +106,11 @@ export class GpuGraph extends SingletonAction<GpuSettings> {
     return gpu && gpu.name ? `GPU ${gpuId} · ${gpu.name}` : `GPU ${gpuId}`;
   }
 }
+
+function parseCombo(raw: string | undefined): string[] | undefined {
+  const ids = (raw ?? "")
+    .split(",")
+    .map((s) => s.trim())
+    .filter(Boolean);
+  return ids.length > 0 ? ids : undefined;
+}