🧹 [Refactor packager main function for readability]

[Tcode-Motion]

🎯 What: The main function in tools/packager/src/main.rs was excessively long and complex, handling everything from directory creation to building tools, copying resources, and packaging installers. This PR extracts those logical blocks into separate, well-named helper functions.
💡 Why: Breaking down this monolithic function drastically improves the readability of the packaging orchestration. The main function now serves as a clear, high-level table of contents for the build pipeline, making it much easier to understand, maintain, and test individual packaging steps in the future.
✅ Verification: The refactoring was applied incrementally and verified using cargo check -p techscript_packager. After all changes were made, cargo test --workspace and cargo fmt --all were executed successfully, ensuring no functionality was altered or broken. Code review confirmed safety and correct scope handling.
✨ Result: The main function is now cleanly abstracted into setup_release_directories, build_and_copy_tools, copy_resources, package_installers, and finalize_release, making the code self-documenting and much easier to navigate.

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PR created automatically by Jules for task 9736293174791145260 started by @Tcode-Motion

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