chore(linear-static-mitc4-shell): retry S4 reference step

phases/index.json

@@ -6,8 +6,7 @@
     },
     {
       "dir": "linear-static-mitc4-shell",
-      "status": "error",
-      "failed_at": "2026-08-12T22:18:45+0900"
+      "status": "pending"
     }
   ]
-}
+}

phases/linear-static-mitc4-shell/index.json

@@ -109,10 +109,8 @@
     {
       "step": 13,
       "name": "shell-reference-comparison",
-      "status": "error",
-      "error_message": "Parser set namespaces and case-insensitive reference identity are corrected; MSVC/CTest passes 144/146, with only the S4 and S4R blocking-U comparison tests failing. The decks differ only by TYPE=S4/S4R (plus heading), both map to one identical FESA-MITC4 stiffness, but Abaqus center U3 differs by 8.190036e-7 while the larger approved tolerance is 1.0245598239e-9, so no common FESA result can pass both references without an upstream mapping or tolerance/gate contract change.",
-      "started_at": "2026-08-12T21:54:14+0900",
-      "failed_at": "2026-08-12T22:18:44+0900"
+      "status": "pending",
+      "started_at": "2026-08-12T21:54:14+0900"
     }
   ],
   "created_at": "2026-08-12T17:50:02+0900"