Initial public release

Aurum — a self-hosted personal finance operating system: cash flow,
net worth tracking, budgets, goals, recurring payments, reports,
proactive alerts, and a compound-interest returns calculator, all
bilingual (RU/EN) and mobile-first. Ships as a three-container Docker
Compose stack (Postgres + FastAPI + nginx-served React frontend).

See README.md for setup and CONTRIBUTING.md for development.

backend/app/schemas/transaction.py

@@ -0,0 +1,63 @@
+from datetime import date as date_
+from decimal import Decimal
+
+from pydantic import BaseModel, ConfigDict, Field, model_validator
+
+from app.models.enums import TransactionType
+from app.schemas.account import AccountRead
+from app.schemas.category import CategoryRead
+
+
+class TransactionBase(BaseModel):
+    account_id: int
+    category_id: int | None = None
+    transfer_account_id: int | None = None
+    type: TransactionType
+    amount: Decimal = Field(gt=0, max_digits=14, decimal_places=2)
+    description: str = Field(min_length=1, max_length=255)
+    merchant: str | None = Field(default=None, max_length=150)
+    notes: str | None = None
+    date: date_
+
+    @model_validator(mode="after")
+    def _validate_type_specific_fields(self) -> "TransactionBase":
+        if self.type == TransactionType.TRANSFER and not self.transfer_account_id:
+            raise ValueError("transfer_account_id is required for transfer transactions")
+        if self.type == TransactionType.TRANSFER and self.transfer_account_id == self.account_id:
+            raise ValueError("transfer_account_id must differ from account_id")
+        if self.type != TransactionType.TRANSFER and self.transfer_account_id:
+            raise ValueError("transfer_account_id is only valid for transfer transactions")
+        if self.type == TransactionType.TRANSFER and self.category_id:
+            raise ValueError("category_id is not valid for transfer transactions")
+        return self
+
+
+class TransactionCreate(TransactionBase):
+    pass
+
+
+class TransactionUpdate(BaseModel):
+    account_id: int | None = None
+    category_id: int | None = None
+    transfer_account_id: int | None = None
+    type: TransactionType | None = None
+    amount: Decimal | None = Field(default=None, gt=0, max_digits=14, decimal_places=2)
+    description: str | None = Field(default=None, min_length=1, max_length=255)
+    merchant: str | None = Field(default=None, max_length=150)
+    notes: str | None = None
+    date: date_ | None = None
+
+
+class TransactionRead(TransactionBase):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    account: AccountRead
+    category: CategoryRead | None = None
+
+
+class TransactionPage(BaseModel):
+    items: list[TransactionRead]
+    total: int
+    page: int
+    page_size: int