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/security.py

@@ -0,0 +1,30 @@
+import hashlib
+import secrets
+
+from argon2 import PasswordHasher
+from argon2.exceptions import InvalidHashError, VerificationError, VerifyMismatchError
+
+_password_hasher = PasswordHasher()
+
+
+def hash_password(password: str) -> str:
+    return _password_hasher.hash(password)
+
+
+def verify_password(password_hash: str, password: str) -> bool:
+    try:
+        return _password_hasher.verify(password_hash, password)
+    except (VerifyMismatchError, VerificationError, InvalidHashError):
+        return False
+
+
+def new_token() -> str:
+    return secrets.token_urlsafe(32)
+
+
+def token_digest(token: str) -> str:
+    return hashlib.sha256(token.encode("utf-8")).hexdigest()
+
+
+def constant_time_equals(left: str, right: str) -> bool:
+    return secrets.compare_digest(left.encode("utf-8"), right.encode("utf-8"))