Refactor Docs ScrollSpy to use IntersectionObserver and fix dist/src mismatch

Replaces legacy scroll listener with `IntersectionObserver` to eliminate layout thrashing.
- Updates `js/docsView.js` with `rootMargin: "-96px 0px -50% 0px"` and correct scroll-up logic.
- Synchronizes `dist/js/docsView.js` to match the source logic exactly.
- Updates benchmarks to use the same logic for verification.
- Updates lint scripts to exclude benchmarks.

Co-authored-by: PR0M3TH3AN <[email protected]>

scripts/check-inline-styles.mjs

@@ -26,6 +26,7 @@ const IGNORED_DIRS = new Set([
   "logs",
   "playwright-report",
   "test-results",
+  "benchmarks",
 ]);
 
 const DIST_SCAN_PREFIXES = new Set([