perf: optimize persist delta gating and diagnostics

tests/graph-layout-solver.mjs

@@ -0,0 +1,76 @@
+import assert from "node:assert/strict";
+
+import { solveLayoutWithJs } from "../ui/graph-layout-solver.js";
+
+const payload = {
+  nodes: [
+    {
+      x: 20,
+      y: 20,
+      vx: 0,
+      vy: 0,
+      pinned: false,
+      radius: 8,
+      regionKey: "objective",
+      regionRect: { x: 0, y: 0, w: 200, h: 160 },
+    },
+    {
+      x: 80,
+      y: 30,
+      vx: 0,
+      vy: 0,
+      pinned: false,
+      radius: 9,
+      regionKey: "objective",
+      regionRect: { x: 0, y: 0, w: 200, h: 160 },
+    },
+    {
+      x: 100,
+      y: 80,
+      vx: 0,
+      vy: 0,
+      pinned: true,
+      radius: 10,
+      regionKey: "objective",
+      regionRect: { x: 0, y: 0, w: 200, h: 160 },
+    },
+  ],
+  edges: [
+    { from: 0, to: 1, strength: 0.8 },
+    { from: 1, to: 2, strength: 0.6 },
+  ],
+  config: {
+    iterations: 32,
+    repulsion: 2200,
+    springK: 0.05,
+    damping: 0.87,
+    centerGravity: 0.02,
+    minGap: 10,
+    speedCap: 3,
+  },
+};
+
+const resultA = solveLayoutWithJs(payload);
+assert.equal(resultA.ok, true);
+assert.ok(resultA.positions instanceof Float32Array);
+assert.equal(resultA.positions.length, payload.nodes.length * 2);
+assert.equal(resultA.diagnostics.solver, "js-worker");
+assert.equal(resultA.diagnostics.nodeCount, 3);
+
+const resultB = solveLayoutWithJs(payload);
+assert.deepEqual(Array.from(resultA.positions), Array.from(resultB.positions));
+
+for (let index = 0; index < payload.nodes.length; index++) {
+  const x = resultA.positions[index * 2];
+  const y = resultA.positions[index * 2 + 1];
+  assert.ok(Number.isFinite(x));
+  assert.ok(Number.isFinite(y));
+  assert.ok(x >= 0 && x <= 200);
+  assert.ok(y >= 0 && y <= 160);
+}
+
+const emptyResult = solveLayoutWithJs({ nodes: [], edges: [] });
+assert.equal(emptyResult.ok, true);
+assert.equal(emptyResult.positions.length, 0);
+
+console.log("graph-layout-solver tests passed");