feat: enhance CategoryShowcaseScroll with manual scroll locking and improved layout adjustments

src/components/robotics/CategoryShowcaseScroll.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useRef, useEffect, useState } from 'react';
+import { useRef, useEffect, useState, useCallback } from 'react';
 import Image from 'next/image';
 import Link from 'next/link';
 import { motion, useScroll, useTransform } from 'framer-motion';
@@ -157,9 +157,12 @@ function CategorySticky() {
     offset: ['start start', 'end end'],
   });
   const [activeIdx, setActiveIdx] = useState(0);
+  const manualLockUntil = useRef<number>(0);
 
   useEffect(() => {
     return scrollYProgress.on('change', (v) => {
+      /* honor manual click for a short window so scroll doesn't override */
+      if (Date.now() < manualLockUntil.current) return;
       const idx = Math.min(
         CATEGORIES.length - 1,
         Math.max(0, Math.floor(v * CATEGORIES.length))
@@ -168,6 +171,12 @@ function CategorySticky() {
     });
   }, [scrollYProgress]);
 
+  const handlePick = useCallback((i: number) => {
+    /* swap in place, no scroll. Lock scroll listener for 1.2s. */
+    manualLockUntil.current = Date.now() + 1200;
+    setActiveIdx(i);
+  }, []);
+
   /* progress bar height */
   const progressHeight = useTransform(scrollYProgress, [0, 1], ['0%', '100%']);
 
@@ -176,17 +185,16 @@ function CategorySticky() {
       ref={containerRef}
       style={{
         position: 'relative',
-        /* 65vh per category — total ~520vh feels responsive, not endless */
+        /* ~50vh per category scroll budget on top of sticky height */
-        height: `${CATEGORIES.length * 65}vh`,
+        height: `calc(100svh + ${CATEGORIES.length * 50}vh)`,
       }}
     >
       <div
         style={{
           position: 'sticky',
           top: '5.5rem',
-          /* fill the viewport — no empty area below the panel during sticky */
+          /* fill the entire viewport — no void below the panel */
           height: 'calc(100svh - 6.5rem)',
-          maxHeight: '780px',
           display: 'grid',
           gridTemplateColumns: 'minmax(0, 0.95fr) minmax(0, 1.05fr)',
           gap: 'clamp(1.5rem, 3vw, 2.5rem)',
@@ -226,13 +234,7 @@ function CategorySticky() {
               <button
                 key={c.id}
                 type="button"
-                onClick={() => {
+                onClick={() => handlePick(i)}
-                  const el = containerRef.current;
-                  if (!el) return;
-                  const rect = el.getBoundingClientRect();
-                  const targetY = window.scrollY + rect.top + (rect.height * (i + 0.5)) / CATEGORIES.length;
-                  window.scrollTo({ top: targetY - window.innerHeight / 2, behavior: 'smooth' });
-                }}
                 style={{
                   display: 'flex',
                   alignItems: 'center',