Decision Eval — automated scoring for architectural alternatives

Invoke after architect proposes 2+ variants, before creating gate:arch.

When to invoke

Invoke this skill when ALL of these are true:

1. An ADR (docs/decisions/ADR-*.md) or ARCH doc (docs/architecture/ARCH-*.md) contains a section with 2 or more named alternatives (look for ## Alternatives Considered, ## Options, or bold-prefixed options like **Option A:**)
2. The architect has not yet created gate:arch
3. The user has not said "skip scoring", "no scoring", or "skip decision-eval"
4. project_size in PROJECT.md is NOT nano

Skip silently (do not even mention) if any condition fails.

How to invoke