fix: pre-landing and adversarial review fixes

- landing.css: hardcode --lp-btn to #60a5fa (lesson 104 — no var(--color-*) in landing.css)
- ScriptBuilderInput: suggestion chips now correctly disabled during generation
- ChatSidebar: wrapper onClick no longer fires onSelect while in confirming state
- SessionHistoryPage: fix loadMoreAiSessions race condition with generation counter;
  flow session tab auto-activates when URL params target flow session filters

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/SessionHistoryPage.tsx

@@ -29,7 +29,11 @@ type TabId = typeof TABS[number]['id']
 export default function SessionHistoryPage() {
   const navigate = useNavigate()
   const [searchParams, setSearchParams] = useSearchParams()
-  const [activeTab, setActiveTab] = useState<TabId>('ai')
+  const [activeTab, setActiveTab] = useState<TabId>(() => {
+    // If URL params target flow session filters, start on flows tab
+    const hasFlowParams = searchParams.get('ticket') || searchParams.get('client') || searchParams.get('tree')
+    return hasFlowParams ? 'flows' : 'ai'
+  })
 
   // ── AI Session state ──
   const [aiSessions, setAiSessions] = useState<AISessionSummary[]>([])
@@ -38,6 +42,7 @@ export default function SessionHistoryPage() {
   const [aiHasMore, setAiHasMore] = useState(false)
   const [aiSearchInput, setAiSearchInput] = useState('')
   const aiSearchTimeout = useRef<ReturnType<typeof setTimeout> | undefined>(undefined)
+  const aiFilterGenRef = useRef(0)
   const [aiFilters, setAiFilters] = useState({
     q: '',
     session_type: '',
@@ -85,6 +90,9 @@ export default function SessionHistoryPage() {
   // ── AI Sessions: fetch ──
   useEffect(() => {
     let cancelled = false
+    const gen = ++aiFilterGenRef.current
+    setAiSessions([])
+    setAiHasMore(false)
     const load = async () => {
       setAiLoading(true)
       try {
@@ -97,7 +105,7 @@ export default function SessionHistoryPage() {
           date_from: aiFilters.date_from || undefined,
           date_to: aiFilters.date_to ? `${aiFilters.date_to}T23:59:59.999Z` : undefined,
         })
-        if (!cancelled) {
+        if (!cancelled && gen === aiFilterGenRef.current) {
           setAiSessions(data)
           setAiHasMore(data.length >= PAGE_SIZE)
         }
@@ -112,6 +120,7 @@ export default function SessionHistoryPage() {
   }, [aiFilters])
 
   const loadMoreAiSessions = async () => {
+    const gen = aiFilterGenRef.current
     setAiLoadingMore(true)
     try {
       const data = await aiSessionsApi.listSessions({
@@ -124,8 +133,10 @@ export default function SessionHistoryPage() {
         date_from: aiFilters.date_from || undefined,
         date_to: aiFilters.date_to ? `${aiFilters.date_to}T23:59:59.999Z` : undefined,
       })
-      setAiSessions(prev => [...prev, ...data])
-      setAiHasMore(data.length >= PAGE_SIZE)
+      if (gen === aiFilterGenRef.current) {
+        setAiSessions(prev => [...prev, ...data])
+        setAiHasMore(data.length >= PAGE_SIZE)
+      }
     } catch {
       toast.error('Failed to load more sessions')
     } finally {