Deepgrain Foundry: move from a claude.ai artifact to a local repository

The game as of artifact version 24, ready for local development with
coding agents.

- Source split from three large files into 52 small ones under src/sim,
  src/render and src/ui, joined in the order in src/manifest.json by
  build.py. The joined code is unchanged apart from comments; every
  headless suite gives the same output, and screenshots in both looks
  are pixel-identical to before.
- Light tidying with no change in behaviour: one movement scan loop,
  shared hazard-stripe and belt shader helpers, unused code removed, a
  shared check helper for the test suites.
- World files can be exported as an ordinary download outside claude.ai.
- Tests: broken old scripts removed, experiments moved to tools/,
  test/run_all.py added. Tools: shot.py (repeatable screenshots),
  where.py, map.py.
- Docs: AGENTS.md, CLAUDE.md, NOTES.md (the owner's to-do inbox),
  docs/PROJECT_MAP.md, DESIGN.md, TESTING.md, systems notes, the
  owner's requests and an agent log.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K9kLmYADKSEjuwUN3rFxDA

tools/perf.py

@@ -0,0 +1,31 @@
+"""Times the renderer and the simulation in a headless browser: light, drawWorld (with and without
+light and glow), the pixel upload and blit, and one simulation tick, in ms. Rebuild first.
+
+  python3 tools/perf.py
+"""
+import sys, pathlib
+from playwright.sync_api import sync_playwright
+root = pathlib.Path(__file__).resolve().parent.parent
+url = (root / 'dist' / 'index.html').as_uri()
+with sync_playwright() as p:
+    b = p.chromium.launch(args=['--enable-gpu-rasterization','--ignore-gpu-blocklist'])
+    pg = b.new_page(viewport={'width': 1440, 'height': 860})
+    pg.goto(url); pg.wait_for_timeout(300)
+    pg.evaluate("startNewWorld(424242, 1024, 640)")
+    pg.wait_for_function('GAME.running === true', timeout=20000)
+    pg.wait_for_timeout(500)
+    res = pg.evaluate('''() => {
+      const t = (f, n) => { const a = performance.now(); for (let k=0;k<n;k++) f(); return ((performance.now()-a)/n).toFixed(2); };
+      const out = {};
+      out.light = t(() => computeLight(), 20);
+      out.drawWorld = t(() => drawWorld(), 20);
+      SET.lighting = 'off'; out.drawWorldNoLight = t(() => drawWorld(), 20); SET.lighting='full';
+      SET.glow = 'off'; out.drawWorldNoGlow = t(() => drawWorld(), 20); SET.glow='low';
+      out.put = t(() => { R.bctx.putImageData(R.img,0,0); }, 20);
+      out.blit = t(() => { R.ctx.drawImage(R.buf, 0, 0, R.bw, R.bh, 0, 0, R.bw*R.zp, R.bh*R.zp); }, 20);
+      out.sim = t(() => simTick(), 60);
+      out.view = [R.bw, R.bh, R.zp, R.lw, R.lh];
+      return out;
+    }''')
+    print(res)
+    b.close()