chore: replace hand-rolled PHI/EULER_GAMMA with Rust 1.94 stdlib consts - spo_bundle.rs: PHI → std::f64::consts::GOLDEN_RATIO - compression_curves.rs: PHI → std::f64::consts::GOLDEN_RATIO - vml.rs: PHI → std::f64::consts::GOLDEN_RATIO - surround_metadata.rs: EULER_GAMMA → std::f64::consts::EULER_GAMMA - Cargo.toml: rust-version bumped from "1.64" to "1.94" gguf_indexer.rs already used GOLDEN_RATIO. Now the whole codebase is unified. https://claude.ai/code/session_01Y69Vnw751w75iVSBRws7o7#63