feat(ci): add cstring header and compiler fallback for ubuntu runner

feat(ci): enable position independent code for linux shared module linking

feat(ci): fix linux build headers and isolation in cpp ci workflows

feat(ci): fix github actions workflows to ensure green checks across runners

feat(engine): upgrade c++20 trading engine nasdaq itch ouch and rigorous ml evaluation

feat(ai): fix grouping method and enhance prompt

feat(ai): fix grouping method and enhance prompt

feat(ai): add hrt grade zero copy orderbook simd alpha engine and purged cv pipeline

feat(ai): add cpp low latency engine and advanced ml alpha models