[codeandsolder]

Summary

Modernizes the workspace for the Rust 1.98 stable line while preserving Rust 1.94 as the compatibility floor.

• switch the virtual Rust 2024 workspace to resolver 3
• use patched Rust 1.98.1 for normal development, current-stable CI, and production builds
• add a dedicated Rust 1.94.1 MSRV lane instead of freezing every build on the MSRV
• make WASM validation perform a real link on current stable, covering Rust 1.96+'s stricter undefined-symbol behavior
• use Cargo 1.97+'s CARGO_BUILD_WARNINGS=deny warning policy rather than warning denial through RUSTFLAGS
• update all three Docker build stages to use the current Rust 1.98 line plus the 1.98.1 patched toolchain
• align README and canonical SKILL guidance with the split MSRV/current-toolchain policy

Compatibility

rust-version = "1.94" remains unchanged. Resolver 3 and the explicit 1.94.1 CI lane enforce that contract while allowing shipping builds to benefit from current compiler fixes.

Validation

CI now validates both the compatibility floor and current stable, including an actual wasm32-unknown-unknown build rather than only cargo check.