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

@@ -202,6 +202,7 @@ Sort lists alphanumerically (literal byte order, ASCII before letters). Apply th
 - **Import specifiers** — sort named imports inside a single statement: `import { encrypt, randomDataKey, wrapKey } from './crypto.mts'`. Imports that say `import type` follow the same rule. Statement _order_ is the project's existing convention (`node:` → external → local → types) — that's separate from specifier order _within_ a statement.
 - **Method / function source placement** — within a module, sort top-level functions alphabetically. Convention: private functions (lowercase / un-exported) sort first, exported functions second. The first-line `export` keyword is the divider.
 - **Array literals** — when the array is a config list, allowlist, or set-like collection. Position-bearing arrays (e.g. argv, anything where index matters semantically) keep their meaningful order.
+- **`Set` constructor arguments** — `new Set([...])` and `new SafeSet([...])` literals. The runtime is order-insensitive, so source order is alphanumeric. Same rationale as Array literals: predictable diffs, no merge conflicts on insertions.
 
 When in doubt, sort. The cost of a sorted list that didn't need to be is approximately zero; the cost of an unsorted list that did need to be is a merge conflict.