feat: added estimate fixed expenses

api/prisma/migrations/20260302010000_add_estimated_fixed_plans/migration.sql

@@ -0,0 +1,6 @@
+ALTER TABLE "FixedPlan"
+ADD COLUMN IF NOT EXISTS "amountMode" TEXT NOT NULL DEFAULT 'fixed',
+ADD COLUMN IF NOT EXISTS "estimatedCents" BIGINT,
+ADD COLUMN IF NOT EXISTS "actualCents" BIGINT,
+ADD COLUMN IF NOT EXISTS "actualCycleDueOn" TIMESTAMP(3),
+ADD COLUMN IF NOT EXISTS "actualRecordedAt" TIMESTAMP(3);

api/prisma/schema.prisma

@@ -70,6 +70,11 @@ model FixedPlan {
   userId       String
   user         User     @relation(fields: [userId], references: [id], onDelete: Cascade)
   name         String
+  amountMode   String   @default("fixed") // "fixed" | "estimated"
+  estimatedCents BigInt?
+  actualCents  BigInt?
+  actualCycleDueOn DateTime?
+  actualRecordedAt DateTime?
   cycleStart   DateTime
   dueOn        DateTime
   totalCents   BigInt