fix(cli): make the architecture legend's split strings explicit

py/implicit-string-concatenation-in-list on PR #625 (architecture.py:147, :151): one table row and one paragraph were split over lines without parentheses; both are now parenthesized, likewise the f-string row ruff ISC004 flags. The new test pins four two-cell rows and one paragraph and fails with a comma inserted.

🎯 Fix: 97 %
💥 Break: 1 %
💸 Cost: –
⏱️ Time: –
🛡️ Security: ~100 %
🏆 Score: 96
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

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

tests/unit/python/cli/build/docs/readme/test_architecture.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+
+import unittest
+
+from cli.build.docs.readme.architecture import _volumes_legend
+
+
+class TestVolumesLegend(unittest.TestCase):
+    def test_each_table_row_is_one_item_with_the_columns_of_the_header(self):
+        rows = [line for line in _volumes_legend() if line.startswith("|")]
+        self.assertEqual([3, 3, 3, 3], [row.count("|") for row in rows])
+        self.assertIn("role not pinned | shared over NFS |", rows[2])
+
+    def test_the_explanation_below_the_table_is_one_paragraph(self):
+        prose = [line for line in _volumes_legend() if line and line[0] != "|"]
+        self.assertEqual(1, len(prose))
+        self.assertTrue(prose[0].startswith("All four conditions must hold"))
+        self.assertTrue(prose[0].endswith("move data without saying so."))
+
+
+if __name__ == "__main__":
+    unittest.main()