feat(brain): add single-stream visual prototype (T-017)

Brain/tests/test_ui_contract.py

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+import re
+import unittest
+from pathlib import Path
+
+
+HTML_PATH = Path(__file__).resolve().parents[2] / "docs" / "design" / "brain" / "index.html"
+
+
+class UIContractTests(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls) -> None:
+        cls.html = HTML_PATH.read_text(encoding="utf-8")
+
+    def test_prototype_is_self_contained_and_labels_fixture_truthfully(self) -> None:
+        self.assertIn("合成回放不等于模型效果", self.html)
+        self.assertIn("离线 HTML 原型数据", self.html)
+        self.assertNotRegex(self.html, r'(?:src|href)=["\']https?://')
+        self.assertNotIn("@import url", self.html)
+
+    def test_accessibility_and_responsive_guards_are_present(self) -> None:
+        required = (
+            'name="viewport"',
+            'class="skip-link"',
+            'aria-live="polite"',
+            ':focus-visible',
+            'prefers-reduced-motion',
+            'min-height: 44px',
+            '@media (max-width: 420px)',
+            '.toolbar { display: grid; grid-template-columns: 1fr; }',
+            '键盘用户可使用右侧坐标表单',
+        )
+        for marker in required:
+            with self.subTest(marker=marker):
+                self.assertIn(marker, self.html)
+
+    def test_no_structural_emoji_or_unescaped_secret_placeholder_in_text(self) -> None:
+        visible_without_script = re.sub(r"<script[\s\S]*?</script>", "", self.html)
+        self.assertNotRegex(visible_without_script, r"[\U0001F300-\U0001FAFF]")
+        self.assertEqual(self.html.count("__BRAIN_DEMO_TOKEN__"), 1)
+
+
+if __name__ == "__main__":
+    unittest.main()