feat(tool-manager): implement foundational portability infrastructure

[adarsh-7-satyam]

Related Issues

Part of the Tool Manager portability and path resolution enhancement work.

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Purpose

This PR introduces the foundational backend infrastructure required for improving portability support within the eSim Tool Manager subsystem.

The primary objective is to establish a clean and extensible architecture for handling portable path resolution and environment-independent tool configurations while preserving compatibility with the ongoing PyQt6 migration work.

This PR serves as the groundwork for future portability-related enhancements and ensures that tool configurations can be managed more reliably across different systems and installation environments.

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Approach

The implementation focuses on creating a foundational portability layer without altering the existing functional behavior of the Tool Manager subsystem.

Key improvements introduced in this PR include:

• Establishing the initial portability infrastructure for the Tool Manager
• Preparing the codebase for centralized path resolution mechanisms
• Improving maintainability and extensibility for future portability features
• Ensuring compatibility with the active PyQt6 migration branch
• Organizing the backend structure to support environment-independent configurations
• Introducing cleaner abstractions for future tool path management logic

Special care has been taken to avoid regressions in the existing PyQt6-integrated workflow while preparing the subsystem for subsequent portability-focused updates.

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Testing

• Verified that the existing Tool Manager functionality remains operational
• Confirmed compatibility with the active PyQt6 migration branch
• Tested the updated infrastructure against existing workflows to ensure no functional regressions were introduced

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Notes

This PR primarily establishes the foundational infrastructure layer. Additional portability and path resolution features will be implemented incrementally in subsequent PRs.