📝 Improve docs after split

development/tooling.md

@@ -174,18 +174,16 @@ rules disabled in `.oxlintrc.json`.
 - The package is intentionally ESM-only (no CommonJS shim), so CJS resolution
   scenarios are out of scope by design, not a bug.
 
-### `tslib` and `type-fest` are deliberately not used
+### `tslib` is deliberately not used
 
 #### Decision (2026-09)
 
-Neither `tslib` nor `type-fest` is a dependency.
+`tslib` is not a dependency.
 
 #### Why
 
 - `tslib` is a runtime helper for old ES3/ES5 targets; this project targets
   ES2024.
-- `type-fest` was never imported.
-- `knip` flagged both, the same signal that keeps the list honest.
 
 ## Git hooks and script wiring