feat: add structured JSON logging to test harness and collect as arti…

[nishiagarwal2006-lang]

Pull Request Description

Resolves #646. Adds a structured logging framework for tests, formatting console/application execution logs as machine-readable JSON entries. Each log line is injected with crucial metadata (timestamps, test name, URL context, log level, and system environment details) and saved as a test artifact.

Type of Change

• 🧪 Testing related changes and improvements
• 🔧 Core test harness utility

Submission Checklist

• All testing harness architecture is stored within tests/harness/
• Includes structured_logger.py — handles JSON formatting and file rotation/writing
• Includes test_structured_logging.py — validation test suite verifying logging output
• Log files include ISO timestamps, test case name context, and component identifiers

Feature Description

What does this add?
It fixes the issue of unstructured test outputs by establishing a custom JsonStructuredFormatter. When tests run, all logs are intercepting and compiled into a single JSON artifact, allowing immediate correlation with backend application logs during post-failure investigations.

How does a developer use it?
Developers simply inject the structured_log fixture into their test cases:

def test_example_flow(structured_log):
    structured_log.info("Initiating system integration handshake.")
    # Automated steps here...