Refactor test files for improved readability and consistency

- Removed unnecessary blank lines and adjusted formatting in test files.
- Ensured consistent use of commas in function calls and assertions across various test cases.
- Updated import statements for better organization and clarity.
- Enhanced mock setups in tests for better isolation and reliability.
- Improved assertions to follow a consistent style for better readability.

app/schemas/common.py

@@ -18,4 +18,4 @@ class StatusResponse(BaseModel):
 class HealthResponse(BaseModel):
     """Health check response."""
 
-    status: str = Field(description="Health status")
+    status: str = Field(description="Health status")