fix: auto-scroll to top for EventFeed and LogViewer

Newest entries appear at the top in descending sort, so auto-scroll
should snap to top instead of bottom.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/design-system/composites/EventFeed/EventFeed.tsx

@@ -81,25 +81,25 @@ export function EventFeed({ events, maxItems = 200, className }: EventFeedProps)
     .filter((e) => activeFilters.size === 0 || activeFilters.has(e.severity))
     .filter((e) => !searchLower || getSearchableText(e).toLowerCase().includes(searchLower))
 
-  // Auto-scroll to bottom
-  const scrollToBottom = useCallback(() => {
+  // Auto-scroll to top (newest entries are at top in desc sort)
+  const scrollToTop = useCallback(() => {
     const el = scrollRef.current
     if (el) {
-      el.scrollTop = el.scrollHeight
+      el.scrollTop = 0
     }
   }, [])
 
   useEffect(() => {
     if (!isPaused) {
-      scrollToBottom()
+      scrollToTop()
     }
-  }, [events, isPaused, scrollToBottom])
+  }, [events, isPaused, scrollToTop])
 
   function handleScroll() {
     const el = scrollRef.current
     if (!el) return
-    const atBottom = el.scrollHeight - el.scrollTop - el.clientHeight < 8
-    setIsPaused(!atBottom)
+    const atTop = el.scrollTop < 8
+    setIsPaused(!atTop)
   }
 
   function toggleFilter(severity: SeverityFilter) {
@@ -196,10 +196,10 @@ export function EventFeed({ events, maxItems = 200, className }: EventFeedProps)
           className={styles.resumeBtn}
           onClick={() => {
             setIsPaused(false)
-            scrollToBottom()
+            scrollToTop()
           }}
         >
-          ↓ Resume auto-scroll
+          &uarr; Scroll to latest
         </button>
       )}
     </div>

src/design-system/composites/LogViewer/LogViewer.tsx

@@ -35,18 +35,18 @@ function formatTime(iso: string): string {
 
 export function LogViewer({ entries, maxHeight = 400, className }: LogViewerProps) {
   const scrollRef = useRef<HTMLDivElement>(null)
-  const isAtBottomRef = useRef(true)
+  const isAtTopRef = useRef(true)
 
   const handleScroll = useCallback(() => {
     const el = scrollRef.current
     if (!el) return
-    isAtBottomRef.current = el.scrollHeight - el.scrollTop - el.clientHeight < 20
+    isAtTopRef.current = el.scrollTop < 20
   }, [])
 
   useEffect(() => {
     const el = scrollRef.current
-    if (el && isAtBottomRef.current) {
-      el.scrollTop = el.scrollHeight
+    if (el && isAtTopRef.current) {
+      el.scrollTop = 0
     }
   }, [entries])