Prepare native engine and formatter crates for registry distribution

[konojunya]

Summary

• Resolve compiler and theme from their exact published crates.io versions.
• Package the native engine and formatter with license notices and generated test assets while keeping the WASM adapter npm-only.
• Add guarded, one-time initial publication workflows for stack-formatter 0.1.0 and stack-engine 0.7.0.

Validation

• Rust stable and 1.85.0 workspace tests, Clippy, rustdoc, formatter package dry-run
• WASM build, 13 browser tests, typecheck, npm package validation
• Layout catalog validation with no layout algorithm or approved snapshot changes
• Coverage: 97.23% lines, 95.68% functions, 95.09% regions
• Publication guard tests, generated asset check, actionlint