Add test coverage

[aaishwarymishra]

Description

Currently, our test coverage for the configuration modules (config) and the base registry needs improvement to ensure long-term stability and prevent regressions.

Additionally, our integration tests currently run directly within the local development Python environment, utilizing already-installed dependencies. This doesn't accurately simulate a clean, end-user installation. When a TOML file and project dependencies are generated dynamically, we should programmatically isolate the test execution environment. Specifically, we should use uv to install the newly generated dependencies and run the tests against that isolated environment.

Tasks & Implementation Plan

1. Unit Testing & Coverage

• Expand config tests: Add edge-case testing for configuration loading, missing fields, invalid TOML/YAML formats, and environment variable overrides.
• Expand registry tests: Add unit tests for base registry registration, lookup failures, duplicate keys, and dynamic loading mechanics.

2. Test Environment Isolation (Integration Tests)

• Introduce uv environment creation: Modify the integration test setup (or specific fixtures) to spin up a temporary, clean virtual environment using uv venv.
• Dynamic Dependency Installation: For tests involving generated TOML files, use uv pip install to explicitly install those generated dependencies into the temporary environment.
• Test Execution Shift: Ensure the integration test suite runs commands/subprocesses targeting the isolated environment's Python binary rather than the active development environment.