feat(routines): add typed Rust scalar ABI projection

[jscott3201]

Summary

• add a typed in-memory scalar ABI projection over ResolvedSpecialization
• preserve scalar order, coordinates, numeric variants, alias metadata, sources, and directions
• lower enums through caller-supplied source-member mappings with deterministic validation
• reject inconsistent manually constructed resolved values without panicking

Validation

• cargo fmt --manifest-path tools/routine-compiler/Cargo.toml -- --check
• cargo test --locked --manifest-path tools/routine-compiler/Cargo.toml — 29 passed
• cargo clippy --locked --manifest-path tools/routine-compiler/Cargo.toml --all-targets -- -D warnings
• focused Python resolution/scalar-ABI suite — 36 passed
• full routine lint discovery — 189 passed
• repository schema, semantic, catalog, G36 source/declaration, verifier, fault-library, and dataset gates

Scope

This remains a Rust-only in-memory stage. It does not add raw JSON validation, serialization, a Python or cxf-json bridge, scalar naming, generated artifacts, or Engine/Studio integration.

[jscott3201]

Review cycle 1 completed against d8b6d1538affeadc69b2319e311ff4233587454e.

Both independent reviewers found no blocker, major, minor, or nit issues. The PR head remains unchanged, and the exact-head build and verify checks passed. No repair cycle is required.