Make pre-commit executable; clarify sanitizer note

Make the .husky/pre-commit script executable and add a POSIX shebang so the hook runs reliably. In src/utils/options.ts, add a clarifying comment explaining that sanitizers return null when the input is already bridge-safe (e.g. trimStringFields), and that using `sanitizer(value) !== null` is a valid dirty-check without a separate traversal. No functional logic changes.

Author: mCodex

.husky/pre-commit

@@ -1 +1,2 @@
+#!/usr/bin/env sh
 yarn lint-staged

src/utils/options.ts

@@ -133,6 +133,9 @@ export const normalizeOptions = (
   if (!options) return undefined
 
   // Fast first pass: detect whether anything needs to change.
+  // Sanitizers return `null` only when the input is already bridge-safe
+  // (see `trimStringFields`), so `sanitizer(value) !== null` is a sound
+  // dirty-check predicate without needing a separate traversal.
   let dirty = false
   const keys = Object.keys(options)