Grid Solutions updates

[abdelrahman-ayad]

Summary

Upgrades PSI/PSY dependencies, migrates the reliability pipeline from PSY2PRAS to SPI, adds HDF5-based results serialization, multi-threads PRAS, and refactors core simulation-creation code — plus a batch of correctness fixes and new tests.

Key changes

• PSI/PSY upgrade: bump to PSI 0.37.0 and update all PSY getters/setters accordingly.
• PSY2PRAS → SPI migration: new spi_utils.jl replaces PSY2PRAS for outage handling and PRAS system construction.
• PRAS improvements: multi-threaded PRAS runs, higher sample count, and use of PRAS's native NEUE instead of manual load-loss calculations.
• HDF5 results serialization: new save/load utilities to checkpoint and store simulation, investment, and market results in .h5 format.
• Simulation structure refactors: significant rework of project, investor, and system creators to reduce redundant computation (deepcopies, repeated CSV reads, availability calculations).
• Bug fixes: infeasible thermal cost curves, ORDC construction, load year typo, bus-name/number mixup, simulation-years default, and total load accounting.
• New tests: HDF5 serialization, PSI compatibility, and base/system pre-checks.

[purboday]

@abdelrahman-ayad Do you need to generate a PRAs system here? I thought we can directly pass a PSY system to PRAS.assess and SPI is called internally?