server: database schema, migrations and seed

Define Prisma schema (Player, City, Good, InventoryItem, Transaction,
Mission, WorldEvent), initial migration SQL, and seed script to
populate cities and goods with base game data.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/prisma/schema.prisma

@@ -0,0 +1,157 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+enum MissionStatus {
+  STARTED
+  COMPLETED
+  FAILED
+}
+
+enum MissionType {
+  DELIVERY
+  THEFT
+  SMUGGLING
+  INTEL
+}
+
+enum EventType {
+  MARKET_BOOM
+  POLICE_RAID
+  SHORTAGE
+  BLACKOUT
+}
+
+model User {
+  id           String   @id @default(uuid())
+  email        String   @unique
+  passwordHash String
+  createdAt    DateTime @default(now())
+  updatedAt    DateTime @updatedAt
+  player       Player?
+}
+
+model Player {
+  id            String   @id @default(uuid())
+  userId        String   @unique
+  displayName   String   @unique
+  money         Int      @default(1000)
+  reputation    Int      @default(0)
+  level         Int      @default(1)
+  experience    Int      @default(0)
+  currentCityId String
+  createdAt     DateTime @default(now())
+  updatedAt     DateTime @updatedAt
+
+  user        User            @relation(fields: [userId], references: [id])
+  currentCity City            @relation(fields: [currentCityId], references: [id])
+  inventory   InventoryItem[]
+  missions    PlayerMission[]
+}
+
+model City {
+  id              String   @id @default(uuid())
+  name            String   @unique
+  riskLevel       Int
+  policePressure  Float    @default(1.0)
+  economyModifier Float    @default(1.0)
+  createdAt       DateTime @default(now())
+
+  players  Player[]
+  prices   MarketPrice[]
+  missions Mission[]
+  events   WorldEvent[]
+}
+
+model Item {
+  id           String   @id @default(uuid())
+  name         String   @unique
+  basePrice    Int
+  rarity       Int
+  illegalLevel Int
+  weight       Int      @default(1)
+  createdAt    DateTime @default(now())
+
+  inventory InventoryItem[]
+  prices    MarketPrice[]
+  missions  Mission[]
+}
+
+model InventoryItem {
+  playerId String
+  itemId   String
+  quantity Int
+
+  player Player @relation(fields: [playerId], references: [id])
+  item   Item   @relation(fields: [itemId], references: [id])
+
+  @@id([playerId, itemId])
+}
+
+model MarketPrice {
+  cityId    String
+  itemId    String
+  buyPrice  Int
+  sellPrice Int
+  demand    Float    @default(1.0)
+  supply    Float    @default(1.0)
+  updatedAt DateTime @updatedAt
+
+  city City @relation(fields: [cityId], references: [id])
+  item Item @relation(fields: [itemId], references: [id])
+
+  @@id([cityId, itemId])
+}
+
+model Mission {
+  id                   String      @id @default(uuid())
+  cityId               String
+  title                String
+  type                 MissionType
+  difficulty           Int
+  durationSeconds      Int
+  rewardMoney          Int
+  rewardXp             Int
+  risk                 Float
+  requiredItemId       String?
+  requiredItemQuantity Int?
+  expiresAt            DateTime
+  createdAt            DateTime    @default(now())
+
+  city           City            @relation(fields: [cityId], references: [id])
+  requiredItem   Item?           @relation(fields: [requiredItemId], references: [id])
+  playerMissions PlayerMission[]
+}
+
+model PlayerMission {
+  id          String        @id @default(uuid())
+  playerId    String
+  missionId   String
+  status      MissionStatus @default(STARTED)
+  startedAt   DateTime      @default(now())
+  completesAt DateTime
+  resolvedAt  DateTime?
+
+  player  Player  @relation(fields: [playerId], references: [id])
+  mission Mission @relation(fields: [missionId], references: [id])
+}
+
+model WorldEvent {
+  id             String    @id @default(uuid())
+  title          String
+  description    String
+  type           EventType
+  cityId         String?
+  priceModifier  Float     @default(1.0)
+  policeModifier Float     @default(1.0)
+  startsAt       DateTime
+  endsAt         DateTime
+  createdAt      DateTime  @default(now())
+
+  city City? @relation(fields: [cityId], references: [id])
+}