chore(claude): document Set constructor argument sort rule

`new Set([...])` and `new SafeSet([...])` arguments are
order-insensitive at runtime, so the source-order convention is
alphanumeric — same rationale as Array literals (predictable diffs,
no merge conflicts on insertions).

Synced from socket-lib's canonical Sorting section.

Author: jdalton

CLAUDE.md

@@ -220,6 +220,7 @@ Configs live in `.config/`:
 - Type properties: required first, then optional; alphabetical within groups
 - Class members: 1) private properties, 2) private methods, 3) public methods (alphabetical)
 - Object properties & destructuring: alphabetical (except semantic ordering)
+- `Set` constructor arguments: `new Set([...])` literals are alphanumeric (runtime is order-insensitive)
 
 ### Testing