Add config and client injection with test reorganization.

Introduce typed config objects, optional adapter injection, and .env loading to simplify testing while preserving env-based defaults for production usage.

Co-authored-by: Cursor <[email protected]>

tests/unit/redis_config_test.py

@@ -0,0 +1,27 @@
+"""Unit tests for RedisConfig."""
+
+from __future__ import annotations
+
+import pytest
+
+from python_repositories.config import RedisConfig
+
+
+def test_from_env_loads_uri(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("REDIS_URI", "redis://example:6379")
+    config = RedisConfig.from_env(use_dotenv=False)
+    assert config.uri == "redis://example:6379"
+
+
+def test_from_env_raises_when_uri_missing(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("REDIS_URI", raising=False)
+    with pytest.raises(Exception):
+        RedisConfig.from_env(use_dotenv=False)
+
+
+def test_from_env_respects_custom_env_var_name(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("CUSTOM_REDIS_URI", "redis://custom:6379")
+    config = RedisConfig.from_env("CUSTOM_REDIS_URI", use_dotenv=False)
+    assert config.uri == "redis://custom:6379"