feat: add 3D model viewer, HUD panel updates, and eskin-finger-sdk submodule

- Add ModelStage component for 3D model rendering
- Update CenterStage to integrate ModelStage viewer
- Expand HudPanel with new functionality
- Add HUD type definitions
- Add je-skin-model.glb 3D model asset
- Add eskin-finger-sdk as git submodule

src/routes/+page.svelte

@@ -33,6 +33,7 @@
     SerialRecordStateResult,
     SerialImportResult,
     SignalTone,
+    StageViewMode,
     WindowControlAction
   } from "$lib/types/hud";
 
@@ -62,6 +63,9 @@
       matrixViewLabel: "矩阵模式",
       matrixViewNumericLabel: "数字矩阵",
       matrixViewDotsLabel: "点矩阵",
+      stageModeLabel: "渲染模式",
+      stageModeWebglLabel: "WebGL",
+      stageModeModelLabel: "3D 模型",
       resetConfigLabel: "恢复默认",
       applyLiveHint: "实时生效 / 矩阵尺寸变更将重建 viewer",
       runtimeReady: "WEBGL2 READY",
@@ -121,6 +125,9 @@
       matrixViewLabel: "Matrix Mode",
       matrixViewNumericLabel: "Numeric",
       matrixViewDotsLabel: "Dots",
+      stageModeLabel: "Render Mode",
+      stageModeWebglLabel: "WebGL",
+      stageModeModelLabel: "3D Model",
       resetConfigLabel: "Reset",
       applyLiveHint: "Live apply / size changes recreate the viewer",
       runtimeReady: "WEBGL2 READY",
@@ -227,6 +234,7 @@
   let rangeMax = DEFAULT_PRESSURE_RANGE_MAX;
   let colorMapPreset: PressureColorMapPreset = "emerald";
   let matrixDisplayMode: MatrixDisplayMode = "dots";
+  let stageViewMode: StageViewMode = "webgl";
   let replayFrames: ReplayFrame[] = [];
   let replayCurrentIndex = 0;
   let replayHasDisplayedFrame = false;
@@ -1644,6 +1652,7 @@
 
   function handleConfigLink(event: CustomEvent<string>): void {
     if (event.detail === "precision-test") {
+      stageViewMode = "webgl";
       isPrecisionTestOpen = !isPrecisionTestOpen;
       isConfigPanelOpen = false;
       isDevKitConfigOpen = false;
@@ -1651,6 +1660,7 @@
     }
 
     if (event.detail === "settings") {
+      stageViewMode = "webgl";
       isPrecisionTestOpen = false;
       isConfigPanelOpen = !isConfigPanelOpen;
       isDevKitConfigOpen = false;
@@ -1743,6 +1753,14 @@
     matrixDisplayMode = event.detail ? "dots" : "numeric";
   }
 
+  function handleStageModeChange(event: CustomEvent<StageViewMode>): void {
+    stageViewMode = event.detail;
+    if (stageViewMode === "model3d") {
+      isPrecisionTestOpen = false;
+      isConfigPanelOpen = false;
+    }
+  }
+
   onMount(() => {
     let disposed = false;
     let unlistenHudStream: UnlistenFn | null = null;
@@ -1838,6 +1856,10 @@
       matrixViewNumericLabel={uiCopy.matrixViewNumericLabel}
       matrixViewDotsLabel={uiCopy.matrixViewDotsLabel}
       {matrixDisplayMode}
+      stageModeLabel={uiCopy.stageModeLabel}
+      stageModeWebglLabel={uiCopy.stageModeWebglLabel}
+      stageModeModelLabel={uiCopy.stageModeModelLabel}
+      {stageViewMode}
       connectActionLabel={uiCopy.connectActionLabel}
       disconnectActionLabel={uiCopy.disconnectActionLabel}
       exportActionLabel={uiCopy.exportActionLabel}
@@ -1860,6 +1882,7 @@
       on:portchange={handlePortChange}
       on:configlink={handleConfigLink}
       on:matrixdisplaytoggle={handleMatrixDisplayToggle}
+      on:stagemodechange={handleStageModeChange}
       on:serialrefresh={handleSerialRefresh}
       on:serialconnect={handleSerialConnect}
       on:serialexport={handleSerialExportRequest}
@@ -1880,6 +1903,7 @@
       bind:rangeMax
       bind:colorMapPreset
       bind:matrixDisplayMode
+      {stageViewMode}
       configPanelTitle={uiCopy.configPanelTitle}
       configPanelHint={uiCopy.configPanelHint}
       matrixSizeLabel={uiCopy.matrixSizeLabel}
@@ -1916,7 +1940,7 @@
       on:replayclose={handleReplayClose}
       on:configclose={() => (isConfigPanelOpen = false)}
     >
-      {#if !isPrecisionTestOpen}
+      {#if !isPrecisionTestOpen && stageViewMode === "webgl"}
         <section class="range-scale" aria-label="Signal Range">
           <p class="range-label">{locale === "zh-CN" ? "范围" : "Range"}</p>
           <div class="range-track">