Define P18 original relationship preservation code contract

docs/plans/original-completion-2026-10-02/work_packages.json

@@ -8494,7 +8494,7 @@
       "D07",
       "D08"
     ],
-    "state": "planned",
+    "state": "in_progress",
     "supplement_ids": [],
     "owner_roles": {
       "implementation": "実装担当（担当者未割当）",
@@ -8503,7 +8503,7 @@
     },
     "legacy_state": "planned",
     "state_scope": "package-level; completed means whole package accepted; partial implementation is not completion",
-    "current_summary": "P18-01 source and legacy-model/save meaning audit started. P18-02/03 planned. Original three-axis versus current generic five-axis difference, ordinary placement attack and irreversible branch acceptance remain incomplete.",
+    "current_summary": "P18-01 actual original/legacy save audit and backend implementation contract prepared. Opus5.5 recommends Astra for migration/atomic restore complexity. Backend code phase remains part of P18-01; no new delivery unit and no acceptance yet. UI and approved initialization remain unmet.",
     "remaining_deliverables": [
       {
         "id": "P18-01",
@@ -8518,10 +8518,16 @@
             "scope": "Original line143 correction and current relationship/duel call-site audit; not acceptance",
             "linked_at_jst": "2026-10-13T13:46:18.655711+09:00",
             "current_game_acceptance_inferred": false
+          },
+          {
+            "path": "docs/plans/original-completion-2026-10-02/execution/p18-01-contract-r01/opus-contract-decision-r01.json",
+            "sha256_at_integration": "e0b7094808385097fba664d9284d967a044d53fc8bd08e9d4a484f1f31d0032f",
+            "scope": "Actual Opus contract/model proposal only, action wait; no implementation acceptance",
+            "current_game_acceptance_inferred": false
           }
         ],
-        "updated_at_jst": "2026-10-13T13:46:18.655711+09:00",
-        "progress_summary": "Started source/legacy-save meaning audit as P24 closure prerequisite. Original Affection/Lust/Netorare and Affection-bound shield maximum remain different from current direction-neutral trust/respect/affection/fear/dependence and independently configured shield_max. No inferred one-to-one migration. Original shield-break onset is confirmed, ordinary co-placement attack generation is unproven. No new implementation worker or acceptance claimed.",
+        "updated_at_jst": "2026-10-13T14:01:57.377446+09:00",
+        "progress_summary": "P18-01 actual original/legacy save audit and backend implementation contract prepared. Opus5.5 recommends Astra for migration/atomic restore complexity. Backend code phase remains part of P18-01; no new delivery unit and no acceptance yet. UI and approved initialization remain unmet.",
         "remaining_gaps": [
           "Implement original three-axis meaning and protagonist Affection-bound shield maximum across model/UI/save.",
           "Preserve old generic five-axis facts without guessed migration; pin new/old/missing/unknown/corrupt save contract.",
@@ -8565,7 +8571,7 @@
     ],
     "cross_cutting_acceptance_scope": "Completion requirements only, not achieved results. Apply each to relevant slices; non-applicable views require a recorded reason.",
     "initial_revision_state": "planned",
-    "updated_at_jst": "2026-10-13T13:46:18.655711+09:00"
+    "updated_at_jst": "2026-10-13T14:01:57.377446+09:00"
   },
   {
     "id": "P19",