Profiler: real-GPU breakdown by zoom, look and scene, with a baseline (t88 phase 0)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/t_perf.js

@@ -0,0 +1,31 @@
+// Profiling fixtures start in the same state after previous scenes and warm-up ticks.
+const fs = require('fs'), path = require('path'), crypto = require('crypto');
+const { load, suite } = require('./harness');
+const { run } = load();
+const { check, done } = suite();
+// Only the fixture's browser shell is stubbed; all simulation functions are real.
+run(`const GAME = {}, R = {particles: [], camX: 0, camY: 0}, SET = {};
+  const document = {querySelectorAll: () => []}; let acc;
+  function enterGame() {} function snapCamera() {}`);
+run(fs.readFileSync(path.join(__dirname, '../tools/perf-scenes.js'), 'utf8'));
+function fixture(name) {
+  run(`perfScene('${name}', 1024, 640);`);
+  const hash = crypto.createHash('sha256');
+  for (const name of ['mat', 'temp', 'flags', 'part', 'awake', 'hot'])
+    hash.update(run(`Buffer.from(${name}.buffer)`));
+  hash.update(run('JSON.stringify([RS, WS, stats])'));
+  return hash.digest('hex');
+}
+const first = fixture('factory');
+check('factory fixture repeats exactly', fixture('factory') === first);
+run('for (let k = 0; k < 600; k++) simTick();');
+check('factory fixture repeats after a warmed simulation', fixture('factory') === first);
+const moved = run('stats.moved');
+run('for (let k = 0; k < 240; k++) simTick();');
+check('factory still transports grains after four seconds', run('stats.moved') > moved + 1000);
+check('both factory feeds remain active', run('machines.filter(m => m && m.type === "silo" && tick - m.pourT < 10).length') === 2);
+check('factory has fuel remaining in both silos', run('machines.filter(m => m && m.type === "silo" && m.sn > 0).length') === 2);
+const heat = fixture('heat');
+fixture('settled');
+check('heat fixture repeats after another scene', fixture('heat') === heat);
+done();