Fix canvas transfer timeouts and move images out of snapshots

tests/canvas-sync.test.mjs

@@ -1,7 +1,7 @@
 import { test } from "node:test";
 import assert from "node:assert/strict";
 import { CanvasSync, canvasPath, canvasPayload, readLocalRecovery } from "../src/lib/canvas-sync.ts";
-import { emptyCanvas, makeCanvasNode } from "../src/lib/canvas.ts";
+import { emptyCanvas, makeCanvasNode, canvasReducer } from "../src/lib/canvas.ts";
 import { loadBoardCanvas } from "../src/lib/canvas-loader.ts";
 function document(text = "") { const doc = emptyCanvas(); const node = makeCanvasNode("text", { x: 0, y: 0 }); node.id = "text"; node.data.text = text; doc.nodes.push(node); return doc; }
 function deferred() { let resolve, reject; const promise = new Promise((yes, no) => { resolve = yes; reject = no; }); return { promise, resolve, reject }; }
@@ -90,3 +90,15 @@ test("board metadata and snapshot begin concurrently without a request waterfall
   const loading = loadBoardCanvas((path) => { started.push(path); return new Promise((resolve) => releases.push(() => resolve(path.endsWith("/canvas") ? { version: 1, document: emptyCanvas() } : { id: "board", workspace_id: "space", kind: "board" }))); }, "space", "board");
   assert.equal(started.length, 2); releases.forEach((release) => release()); await loading;
 });
+
+
+test("viewport restoration roundoff does not create an autosave", async () => {
+ const doc=document("keep");doc.viewport={x:132.834729193,y:-73.098456241,zoom:0.637185392};
+ const state={past:[],present:doc,future:[]};
+ const next=canvasReducer(state,{type:"viewport",viewport:{x:doc.viewport.x+1e-10,y:doc.viewport.y,zoom:doc.viewport.zoom+1e-12}});
+ assert.equal(next,state);let writes=0;const writer=new CanvasSync(async()=>{writes++;return {version:2};},"canvas",{version:1,document:doc},()=>{});
+ await writer.enqueue(next.present);assert.equal(writes,0);
+ const edited=canvasReducer(state,{type:"viewport",viewport:{...doc.viewport,x:doc.viewport.x+10}});await writer.enqueue(edited.present);assert.equal(writes,0);
+ edited.present.nodes[0]={...edited.present.nodes[0],data:{...edited.present.nodes[0].data,text:"changed"}};
+ await writer.enqueue(edited.present);assert.equal(writes,1);
+});