refactor(sessions): merge Flow and AI sessions into unified view

Remove the Flow/AI session type toggle tabs. Both session types now
display on a single page — FlowPilot sessions at top, flow sessions
below, each with their own filters.

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

frontend/src/pages/SessionHistoryPage.tsx

@@ -21,8 +21,6 @@ export function SessionHistoryPage() {
   const navigate = useNavigate()
   const [searchParams, setSearchParams] = useSearchParams()
 
-  // Top-level tab: flow sessions vs AI sessions
-  const [sessionType, setSessionType] = useState<'flow' | 'ai'>('flow')
   const [aiSessions, setAiSessions] = useState<AISessionSummary[]>([])
   const [aiLoading, setAiLoading] = useState(false)
   const [aiSearchInput, setAiSearchInput] = useState('')
@@ -166,9 +164,8 @@ export function SessionHistoryPage() {
     setSearchParams(params, { replace: true })
   }, [filters, setSearchParams])
 
-  // Load AI sessions when tab is active or filters change
+  // Load AI sessions always
   useEffect(() => {
-    if (sessionType !== 'ai') return
     let cancelled = false
     const loadAiSessions = async () => {
       setAiLoading(true)
@@ -190,7 +187,7 @@ export function SessionHistoryPage() {
     }
     loadAiSessions()
     return () => { cancelled = true }
-  }, [sessionType, aiFilters])
+  }, [aiFilters])
 
   const handleFilterChange = (newFilters: SessionFilterState) => {
     setFilters(newFilters)
@@ -267,66 +264,55 @@ export function SessionHistoryPage() {
     return labels[outcome] ?? outcome
   }
 
+  const hasAiFiltersActive = !!(aiSearchInput || aiFilters.q || aiFilters.problem_domain || aiFilters.confidence_tier || aiFilters.date_from || aiFilters.date_to)
+  const hasFlowFiltersActive = !!(filters.ticketNumber || filters.clientName || filters.treeName || filters.dateRange?.from)
+
+  // Determine section visibility
+  const showAiSection = aiLoading || aiSessions.length > 0 || hasAiFiltersActive
+  const showFlowSection = isLoading || sessions.length > 0 || hasFlowFiltersActive
+  const showCombinedEmpty = !showAiSection && !showFlowSection
+
   return (
     <div className="overflow-y-auto h-full">
-    <PageMeta title="Session History" />
+    <PageMeta title="Sessions" />
     <div className="container mx-auto px-4 py-6 sm:px-6 sm:py-8">
       <div className="mb-8">
-        <h1 className="text-2xl font-heading font-bold text-foreground sm:text-3xl">Session History</h1>
+        <h1 className="text-2xl font-heading font-bold text-foreground sm:text-3xl">Sessions</h1>
         <p className="mt-2 text-muted-foreground">
-          Search and filter your troubleshooting sessions
+          View and manage all your sessions
         </p>
       </div>
 
-      {/* Session type toggle */}
-      <div className="mb-4 flex gap-1 rounded-lg bg-card/50 p-1 w-fit border border-border">
-        <button
-          onClick={() => setSessionType('flow')}
-          className={cn(
-            'rounded-md px-4 py-1.5 text-sm font-medium transition-colors',
-            sessionType === 'flow'
-              ? 'bg-primary/10 text-foreground'
-              : 'text-muted-foreground hover:text-foreground'
-          )}
-        >
-          Flow Sessions
-        </button>
-        <button
-          onClick={() => setSessionType('ai')}
-          className={cn(
-            'rounded-md px-4 py-1.5 text-sm font-medium transition-colors',
-            sessionType === 'ai'
-              ? 'bg-primary/10 text-foreground'
-              : 'text-muted-foreground hover:text-foreground'
-          )}
-        >
-          AI Sessions
-        </button>
-      </div>
-
-      {/* Filter Tabs (flow sessions only) */}
-      {sessionType === 'flow' && (
-      <div className="mb-6 flex gap-2 border-b border-border">
-        {(['active', 'prepared', 'completed', 'all'] as const).map((tab) => (
-          <button
-            key={tab}
-            onClick={() => setFilter(tab)}
-            className={cn(
-              'px-4 py-2 text-sm font-medium transition-colors',
-              filter === tab
-                ? 'border-b-2 border-primary text-foreground'
-                : 'text-muted-foreground hover:text-foreground'
-            )}
-          >
-            {tab.charAt(0).toUpperCase() + tab.slice(1)}
-          </button>
-        ))}
-      </div>
+      {showCombinedEmpty && (
+        <EmptyState
+          illustration={<SessionIllustration />}
+          title="No sessions yet"
+          description="Start a flow or FlowPilot session to begin. All your sessions will appear here."
+          action={
+            <div className="flex gap-3">
+              <Link
+                to="/trees"
+                className="inline-flex items-center gap-2 rounded-[10px] bg-gradient-brand px-5 py-2.5 text-sm font-semibold text-[#101114] shadow-lg shadow-primary/20 hover:opacity-90 active:scale-[0.97] transition-all"
+              >
+                Start a Flow
+              </Link>
+              <Link
+                to="/pilot"
+                className="inline-flex items-center gap-2 rounded-[10px] border border-border bg-[rgba(255,255,255,0.04)] px-5 py-2.5 text-sm font-semibold text-foreground hover:border-[rgba(255,255,255,0.12)] transition-all"
+              >
+                Start AI Session
+              </Link>
+            </div>
+          }
+          learnMoreLink="/guides/sessions"
+        />
       )}
 
-      {/* AI Sessions view */}
-      {sessionType === 'ai' && (
+      {/* FlowPilot Sessions Section */}
+      {showAiSection && (
         <>
+          <h2 className="font-label text-[0.625rem] uppercase tracking-[0.1em] text-muted-foreground mb-3">FlowPilot Sessions</h2>
+
           {/* AI Session Filter Bar */}
           <div className="glass-card-static p-3 mb-4">
             <div className="flex flex-wrap gap-3 items-center">
@@ -400,7 +386,7 @@ export function SessionHistoryPage() {
               </div>
 
               {/* Clear filters */}
-              {(aiSearchInput || aiFilters.q || aiFilters.problem_domain || aiFilters.confidence_tier || aiFilters.date_from || aiFilters.date_to) && (
+              {hasAiFiltersActive && (
                 <button
                   onClick={() => {
                     setAiSearchInput('')
@@ -419,36 +405,21 @@ export function SessionHistoryPage() {
               <Spinner />
             </div>
           ) : aiSessions.length === 0 ? (
-            (aiSearchInput || aiFilters.q || aiFilters.problem_domain || aiFilters.confidence_tier || aiFilters.date_from || aiFilters.date_to) ? (
-              <EmptyState
-                title="No sessions match your filters"
-                description="Try adjusting your search or filters."
-                action={
-                  <button
-                    onClick={() => {
-                      setAiSearchInput('')
-                      setAiFilters({ q: '', problem_domain: '', confidence_tier: '', date_from: '', date_to: '' })
-                    }}
-                    className="text-foreground hover:underline text-sm"
-                  >
-                    Clear all filters
-                  </button>
-                }
-              />
-            ) : (
-              <EmptyState
-                title="No AI sessions yet"
-                description="Start a FlowPilot session to get AI-guided troubleshooting. Sessions will appear here."
-                action={
-                  <Link
-                    to="/pilot"
-                    className="inline-flex items-center gap-2 rounded-[10px] bg-gradient-brand px-5 py-2.5 text-sm font-semibold text-[#101114] shadow-lg shadow-primary/20 hover:opacity-90 active:scale-[0.97] transition-all"
-                  >
-                    Start AI Session
-                  </Link>
-                }
-              />
-            )
+            <EmptyState
+              title="No sessions match your filters"
+              description="Try adjusting your search or filters."
+              action={
+                <button
+                  onClick={() => {
+                    setAiSearchInput('')
+                    setAiFilters({ q: '', problem_domain: '', confidence_tier: '', date_from: '', date_to: '' })
+                  }}
+                  className="text-foreground hover:underline text-sm"
+                >
+                  Clear all filters
+                </button>
+              }
+            />
           ) : (
             <div className="space-y-2">
               {aiSessions.map((s) => (
@@ -456,12 +427,37 @@ export function SessionHistoryPage() {
               ))}
             </div>
           )}
+
+          {/* Divider between sections */}
+          {showFlowSection && (
+            <div className="my-8 border-t border-border" />
+          )}
         </>
       )}
 
-      {/* Flow Sessions Content */}
-      {sessionType === 'flow' && (
+      {/* Flow Sessions Section */}
+      {showFlowSection && (
       <>
+      <h2 className="font-label text-[0.625rem] uppercase tracking-[0.1em] text-muted-foreground mb-3">Flow Sessions</h2>
+
+      {/* Filter Tabs */}
+      <div className="mb-6 flex gap-2 border-b border-border">
+        {(['active', 'prepared', 'completed', 'all'] as const).map((tab) => (
+          <button
+            key={tab}
+            onClick={() => setFilter(tab)}
+            className={cn(
+              'px-4 py-2 text-sm font-medium transition-colors',
+              filter === tab
+                ? 'border-b-2 border-primary text-foreground'
+                : 'text-muted-foreground hover:text-foreground'
+            )}
+          >
+            {tab.charAt(0).toUpperCase() + tab.slice(1)}
+          </button>
+        ))}
+      </div>
+
       <div className="mb-6">
         <SessionFilters
           filters={filters}