Render complete Steam artwork for every sideload and fix VR shortcut identity

Add optional SteamGridDB settings, source-first fallbacks rendered with Steam canvas, backfill commands and shared APK/native library details. Verify live artwork and Open Saber Steam Play/Stop; document SuperTux's clipboard crash.

Co-Authored-By: GPT-6 Astra <noreply@openai.com>

tests/fakeframe/rootfs/usr/local/lib/fakeframe/canvas_stub.js

@@ -0,0 +1,32 @@
+// Synthetic canvas for API-path tests only. It emits transparent PNGs, not visual proof.
+const zlib = require('zlib');
+function crc(data) {
+  let c=0xffffffff;
+  for(const b of data) {c^=b;for(let i=0;i<8;i++)c=(c>>>1)^((c&1)?0xedb88320:0);}
+  return (c^0xffffffff)>>>0;
+}
+function chunk(name,data) {
+  const body=Buffer.concat([Buffer.from(name),data]), n=Buffer.alloc(4), sum=Buffer.alloc(4);
+  n.writeUInt32BE(data.length);sum.writeUInt32BE(crc(body));return Buffer.concat([n,body,sum]);
+}
+function png(w,h) {
+  const header=Buffer.alloc(13);header.writeUInt32BE(w);header.writeUInt32BE(h,4);header[8]=8;header[9]=6;
+  return Buffer.concat([Buffer.from('89504e470d0a1a0a','hex'),chunk('IHDR',header),
+    chunk('IDAT',zlib.deflateSync(Buffer.alloc((w*4+1)*h))),chunk('IEND',Buffer.alloc(0))]).toString('base64');
+}
+function surface() {
+  const canvases=[];
+  const document={fonts:{load:async()=>[]},createElement(tag) {
+    if(tag!=='canvas')throw Error('unexpected element');
+    const canvas={width:1,height:1,text:[],draws:0};
+    const ctx={measureText:t=>({width:String(t).length*30}),fillText(t){canvas.text.push(t);},
+      drawImage(){canvas.draws++;},getImageData:()=>({data:new Uint8ClampedArray(canvas.width*canvas.height*4)}),
+      createLinearGradient:()=>({addColorStop(){}}),createRadialGradient:()=>({addColorStop(){}})};
+    for(const method of ['save','restore','beginPath','rect','roundRect','clip','fillRect','putImageData','arc','fill','stroke'])ctx[method]=()=>{};
+    canvas.getContext=()=>ctx;canvas.toDataURL=()=> 'data:image/png;base64,'+png(canvas.width,canvas.height);
+    canvases.push(canvas);return canvas;
+  }};
+  class Image {constructor(){this.width=2;this.height=2;} async decode(){if(this.src.includes('YmFk'))throw Error('bad image');}}
+  return {document,Image,canvases};
+}
+module.exports={surface};

tests/fakeframe/rootfs/usr/local/lib/fakeframe/cef_shim.js

@@ -37,7 +37,7 @@ function build(steam) {
     },
   });
   const shortcutOverview = s => ({
-    appid: s.appid, display_name: s.name, sort_as: s.name, app_type: SHORTCUT_TYPE,
+    appid: s.appid, display_name: s.name, sort_as: s.name, app_type: SHORTCUT_TYPE, devkit_gameid: s.devkit_gameid,
     local_per_client_data: { installed: true, display_status: 1, status_percentage: 0 },
   });
   const allApps = () => [...steam.apps.map(gameOverview), ...steam.shortcuts.map(shortcutOverview)];
@@ -65,6 +65,7 @@ function build(steam) {
     value,
   });
   return {
+    ...require('./canvas_stub').surface(),
     collectionStore: {
       GetUserCollectionsByName(name) { return steam.collections.filter(c => c.name === name).map(collection); },
       NewUnsavedCollection(name, filter, apps) { return collection({name, apps: apps.map(a => a.appid)}); },