feat: add tests for import polling, login page, money utilities, and query keys

- Implemented tests for import polling functionality, ensuring correct behavior for active and terminal import statuses.
- Created tests for the login page, validating user interactions and error handling.
- Added unit tests for money utility functions, covering parsing, formatting, and summation of monetary values.
- Developed tests for query keys, ensuring proper scoping and invalidation roots.

chore: setup testing environment and configuration

- Added setup file for testing with Vitest and Testing Library.
- Configured TypeScript and Vite for the frontend project.
- Created Docker and Nginx configurations for local development and production environments.
- Established a PostgreSQL initialization script for setting up application roles.

docs: add README and environment configuration for infra

- Included README for the infra directory, detailing local development setup and service descriptions.
- Created an example environment configuration file for local development with placeholders for sensitive information.

backend/app/spaces/models.py

@@ -0,0 +1,28 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import ForeignKey, String, UniqueConstraint, Uuid
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base import Base, PkMixin, TimestampMixin, UTCDateTime
+
+
+class FinancialSpace(Base, PkMixin, TimestampMixin):
+    __tablename__ = "financial_spaces"
+
+    name: Mapped[str] = mapped_column(String(200), nullable=False)
+    status: Mapped[str] = mapped_column(String(16), nullable=False, default="active")
+    deletion_scheduled_at: Mapped[datetime | None] = mapped_column(UTCDateTime(), nullable=True)
+
+
+class Membership(Base, PkMixin, TimestampMixin):
+    __tablename__ = "memberships"
+    __table_args__ = (UniqueConstraint("space_id", "user_id", name="uq_memberships_space_user"),)
+
+    space_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    role: Mapped[str] = mapped_column(String(16), nullable=False, default="member")