feat(02-01): Account and AccountingPeriod Prisma models + COA definition

- Add AccountType, NormalBalance, PeriodStatus enums to schema
- Add Account model with tenant scoping, code/name/type/normalBalance/parentId
- Add AccountingPeriod model with year/month/status/closedAt/closedById
- Create ISP_CHART_OF_ACCOUNTS with 28 accounts across all 5 types (1000-5000 ranges)
- Create accounting-period.ts with getOpenPeriod, closePeriod, isDateInClosedPeriod
- Extend TENANT_SCOPED_MODELS with account and accountingPeriod
- Add full query extension blocks for account and accountingPeriod in withTenantContext
- Run migration: 20260304144656_add_accounting_models

prisma/migrations/20260304144656_add_accounting_models/migration.sql

@@ -0,0 +1,57 @@
+-- CreateEnum
+CREATE TYPE "AccountType" AS ENUM ('ASSET', 'LIABILITY', 'EQUITY', 'REVENUE', 'EXPENSE');
+
+-- CreateEnum
+CREATE TYPE "NormalBalance" AS ENUM ('DEBIT', 'CREDIT');
+
+-- CreateEnum
+CREATE TYPE "PeriodStatus" AS ENUM ('OPEN', 'CLOSED');
+
+-- CreateTable
+CREATE TABLE "Account" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "code" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "accountType" "AccountType" NOT NULL,
+    "normalBalance" "NormalBalance" NOT NULL,
+    "parentId" TEXT,
+    "isSystemAccount" BOOLEAN NOT NULL DEFAULT true,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Account_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "AccountingPeriod" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "year" INTEGER NOT NULL,
+    "month" INTEGER NOT NULL,
+    "status" "PeriodStatus" NOT NULL DEFAULT 'OPEN',
+    "closedAt" TIMESTAMP(3),
+    "closedById" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "AccountingPeriod_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE INDEX "Account_tenantId_idx" ON "Account"("tenantId");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "Account_tenantId_code_key" ON "Account"("tenantId", "code");
+
+-- CreateIndex
+CREATE INDEX "AccountingPeriod_tenantId_idx" ON "AccountingPeriod"("tenantId");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "AccountingPeriod_tenantId_year_month_key" ON "AccountingPeriod"("tenantId", "year", "month");
+
+-- AddForeignKey
+ALTER TABLE "Account" ADD CONSTRAINT "Account_parentId_fkey" FOREIGN KEY ("parentId") REFERENCES "Account"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "AccountingPeriod" ADD CONSTRAINT "AccountingPeriod_closedById_fkey" FOREIGN KEY ("closedById") REFERENCES "User"("id") ON DELETE SET NULL ON UPDATE CASCADE;

prisma/schema.prisma

@@ -39,6 +39,24 @@ enum Role {
   CLIENT
 }
 
+enum AccountType {
+  ASSET
+  LIABILITY
+  EQUITY
+  REVENUE
+  EXPENSE
+}
+
+enum NormalBalance {
+  DEBIT
+  CREDIT
+}
+
+enum PeriodStatus {
+  OPEN
+  CLOSED
+}
+
 // =============================================================================
 // MODELS
 // =============================================================================
@@ -69,6 +87,56 @@ model Tenant {
   users User[]
 }
 
+/// An Account represents a node in the Chart of Accounts tree.
+/// Account balances are NEVER stored — they are always derived from journal entry sums.
+/// System accounts (isSystemAccount=true) are auto-created from ISP_CHART_OF_ACCOUNTS
+/// and cannot be deleted by tenant admins.
+model Account {
+  id            String        @id @default(uuid())
+  tenantId      String
+  /// Account code (e.g., "1010" for Cash on Hand). Unique per tenant.
+  code          String
+  name          String
+  accountType   AccountType
+  normalBalance NormalBalance
+  /// Optional parent account id for hierarchical COA (e.g., 1010 parent = 1000)
+  parentId      String?
+  parent        Account?      @relation("AccountSubAccounts", fields: [parentId], references: [id])
+  children      Account[]     @relation("AccountSubAccounts")
+  /// COA accounts seeded at tenant creation cannot be deleted by admins
+  isSystemAccount Boolean     @default(true)
+  createdAt     DateTime      @default(now())
+  updatedAt     DateTime      @updatedAt
+
+  /// Account codes must be unique within a tenant
+  @@unique([tenantId, code])
+  /// RLS-ready index — always present on tenant-scoped models
+  @@index([tenantId])
+}
+
+/// An AccountingPeriod represents one calendar month for a tenant.
+/// Once CLOSED, no journal entries may be posted to that period.
+/// Periods are created on-demand (first time an entry needs one).
+model AccountingPeriod {
+  id          String       @id @default(uuid())
+  tenantId    String
+  year        Int
+  month       Int
+  status      PeriodStatus @default(OPEN)
+  /// Timestamp when the period was closed (null if OPEN)
+  closedAt    DateTime?
+  /// The admin user who closed this period
+  closedById  String?
+  closedBy    User?        @relation(fields: [closedById], references: [id])
+  createdAt   DateTime     @default(now())
+  updatedAt   DateTime     @updatedAt
+
+  /// One period per month per tenant
+  @@unique([tenantId, year, month])
+  /// RLS-ready index — always present on tenant-scoped models
+  @@index([tenantId])
+}
+
 /// A User belongs to a Tenant (or is a super-admin with no tenant).
 /// Email uniqueness is enforced per-tenant, not globally.
 /// Super-admins have isSuperAdmin=true and tenantId=null.
@@ -89,6 +157,9 @@ model User {
   isActive     Boolean @default(true)
   isSuperAdmin Boolean @default(false)
 
+  /// Accounting periods this user has closed (as administrator)
+  closedPeriods AccountingPeriod[]
+
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt