feat: 외교부 기능 추가 및 외교 문서 관련 데이터베이스 모델 생성

packages/infra/prisma/game.prisma

@@ -37,6 +37,13 @@ enum AuctionType {
     UNIQUE_ITEM
 }
 
+enum DiplomacyLetterState {
+    PROPOSED
+    ACTIVATED
+    CANCELLED
+    REPLACED
+}
+
 model WorldState {
     id           Int      @id @default(autoincrement())
     scenarioCode String   @map("scenario_code")
@@ -187,6 +194,25 @@ model Diplomacy {
     @@map("diplomacy")
 }
 
+model DiplomacyLetter {
+    id           Int                  @id @default(autoincrement())
+    srcNationId  Int                  @map("src_nation_id")
+    destNationId Int                  @map("dest_nation_id")
+    prevId       Int?                 @map("prev_id")
+    state        DiplomacyLetterState @default(PROPOSED)
+    textBrief    String               @map("text_brief")
+    textDetail   String               @map("text_detail")
+    date         DateTime             @default(now()) @map("date")
+    srcSignerId  Int                  @map("src_signer")
+    destSignerId Int?                 @map("dest_signer")
+    aux          Json                 @default(dbgenerated("'{}'::jsonb"))
+
+    @@index([srcNationId, destNationId])
+    @@index([destNationId, srcNationId])
+    @@index([state, date])
+    @@map("diplomacy_letter")
+}
+
 model Event {
     id         Int      @id @default(autoincrement())
     targetCode String   @map("target_code")

packages/infra/prisma/migrations/20260128001000_add_diplomacy_letters/migration.sql

@@ -0,0 +1,19 @@
+CREATE TYPE "diplomacy_letter_state" AS ENUM ('PROPOSED', 'ACTIVATED', 'CANCELLED', 'REPLACED');
+
+CREATE TABLE "diplomacy_letter" (
+    "id" SERIAL PRIMARY KEY,
+    "src_nation_id" INTEGER NOT NULL,
+    "dest_nation_id" INTEGER NOT NULL,
+    "prev_id" INTEGER,
+    "state" "diplomacy_letter_state" NOT NULL DEFAULT 'PROPOSED',
+    "text_brief" TEXT NOT NULL,
+    "text_detail" TEXT NOT NULL,
+    "date" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "src_signer" INTEGER NOT NULL,
+    "dest_signer" INTEGER,
+    "aux" JSONB NOT NULL DEFAULT '{}'::jsonb
+);
+
+CREATE INDEX "diplomacy_letter_src_dest_idx" ON "diplomacy_letter"("src_nation_id", "dest_nation_id");
+CREATE INDEX "diplomacy_letter_dest_src_idx" ON "diplomacy_letter"("dest_nation_id", "src_nation_id");
+CREATE INDEX "diplomacy_letter_state_date_idx" ON "diplomacy_letter"("state", "date");

packages/infra/src/db.ts

@@ -9,6 +9,7 @@ export interface DatabaseClient {
     city: GamePrisma.CityDelegate;
     nation: GamePrisma.NationDelegate;
     diplomacy: GamePrisma.DiplomacyDelegate;
+    diplomacyLetter: GamePrisma.DiplomacyLetterDelegate;
     generalTurn: GamePrisma.GeneralTurnDelegate;
     nationTurn: GamePrisma.NationTurnDelegate;
     troop: GamePrisma.TroopDelegate;