fix(3d): unified conveyorNetwork, physical B receiver, C/D containment, belt sync, real STL

scripts/qa_before.py

@@ -0,0 +1,19 @@
+from pathlib import Path
+from playwright.sync_api import sync_playwright
+out = Path('docs/final_physics_fix_screenshots/before')
+out.mkdir(parents=True, exist_ok=True)
+with sync_playwright() as p:
+    browser = p.chromium.launch(headless=True)
+    page = browser.new_page(viewport={"width":1440,"height":900})
+    errs=[]
+    page.on('console', lambda m: errs.append(f"{m.type}: {m.text}") if m.type=='error' else None)
+    page.on('pageerror', lambda e: errs.append(f"pageerror: {e}"))
+    page.goto('https://arhipovdan.ru/?qa=before', wait_until='networkidle')
+    page.wait_for_timeout(2000)
+    page.screenshot(path=str(out/'before_idle.png'), full_page=True)
+    page.get_by_label('Play demo').click()
+    for i in range(12):
+        page.wait_for_timeout(1500)
+        page.screenshot(path=str(out/f'before_t{i:02d}.png'), full_page=True)
+    print("ERRORS:" + "\n".join(errs) if errs else "NO_CONSOLE_ERRORS")
+    browser.close()