Fix headless path helpers for relative data loads

[tinycrops]

Summary

• make GetScriptPath() return the actual headless working directory instead of an empty string
• derive GetRuntimePath() and GetUserPath() from that resolved path
• fix headless imports that load data files relative to the script root

Repro

• run headless PoB with loadBuildFromJSON(...) on a character that has a timeless jewel allocated
• Modules/DataLegionLookUpTableHelper.lua builds lookup-table paths from GetScriptPath()
• in headless mode the wrapper currently returns "", so those paths resolve to /Data/TimelessJewelData/... instead of the mounted PoB checkout
• this causes timeless-jewel imports to fail even though the data files are present

Result

• headless JSON imports can now resolve timeless jewel data from src/Data/TimelessJewelData
• this unblocks headless stat extraction for builds that allocate timeless jewels