fix: 삭제 메시지를 tombstone으로 보존한다

메시지 삭제 시 유효기간을 만료시키지 않고 본문을 삭제 안내로 치환해 송수신 행을 유지한다. 외교 메시지 조회 권한 부족은 삭제 상태와 분리하고 API, PostgreSQL 통합, Chromium 회귀 검증을 추가한다.

app/game-api/src/messages/store.ts

@@ -1,8 +1,8 @@
+import { enqueuePrivateMessageWebPush, GamePrisma } from '@sammo-ts/infra';
 import type { MessagePayload, MessageRecordDraft, MessageType } from '@sammo-ts/logic';
 
 import type { DatabaseClient } from '../context.js';
 import { loadCurrentGameTime } from '../services/gameClock.js';
-import { enqueuePrivateMessageWebPush } from '@sammo-ts/infra';
 
 export interface MessageView {
     id: number;
@@ -203,3 +203,26 @@ export const invalidateMessages = async (db: DatabaseClient, ids: number[]): Pro
         },
     });
 };
+
+export const tombstoneMessages = async (db: DatabaseClient, ids: number[]): Promise<void> => {
+    const uniqueIds = Array.from(new Set(ids.filter((id) => Number.isInteger(id) && id > 0)));
+    if (uniqueIds.length === 0) return;
+
+    await db.$executeRaw(
+        GamePrisma.sql`
+            UPDATE message
+            SET message = jsonb_set(
+                jsonb_set(message, '{text}', to_jsonb(${'삭제된 메시지입니다.'}::text), true),
+                '{option}',
+                (
+                    CASE
+                        WHEN jsonb_typeof(message->'option') = 'object' THEN message->'option'
+                        ELSE '{}'::jsonb
+                    END
+                ) || jsonb_build_object('invalid', true),
+                true
+            )
+            WHERE id IN (${GamePrisma.join(uniqueIds)})
+        `
+    );
+};

app/game-api/src/router/messages/index.ts

@@ -19,8 +19,8 @@ import {
     fetchMessagesFromMailbox,
     fetchOldMessagesFromMailbox,
     fetchMessageById,
-    invalidateMessages,
     insertMessage,
+    tombstoneMessages,
     type MessageView,
 } from '../../messages/store.js';
 import { getOwnedGeneral } from '../shared/general.js';
@@ -40,11 +40,7 @@ const redactDiplomacyMessages = (messages: MessageView[], permission: number): M
         }
         return {
             ...message,
-            text: '(외교 메시지입니다)',
-            option: {
-                ...(message.option ?? {}),
-                invalid: true,
-            },
+            text: '조회 권한이 없는 외교 메시지입니다.',
         };
     });
 };
@@ -303,7 +299,7 @@ export const messagesRouter = router({
                 message.id,
                 ...(shouldDeleteReceiverCopy && typeof receiverMessageId === 'number' ? [receiverMessageId] : []),
             ];
-            await invalidateMessages(ctx.db, ids);
+            await tombstoneMessages(ctx.db, ids);
             const receiverMailbox =
                 shouldDeleteReceiverCopy && typeof receiverMessageId === 'number' && message.msgType === 'private'
                     ? message.payload.dest.generalId