feat(escalations): close out plan-locked wedge polish

Four items from the design-plan audit, all flagged as locked-design or
Codex corrections, shipped together so the GTM demo path covers them
end-to-end before bug bash.

1. Live AI assessment refresh on the magic-moment screen. Backend already
   publishes handoff_assessment_ready when enrich_escalation_async commits;
   wire the frontend listener so the senior sees the assessment populate
   without a manual reopen. New event type + onAssessmentReady handler on
   streamEscalations; AssistantChatPage opens a scoped SSE subscription
   whenever it tracks a handoff missing its assessment, refetches on match,
   and replaces magicHandoff / overlayHandoff in place. Closes the loop on
   the async-assessment commit e8ba74e.

2. Suggested-step chips below the chat input. Locked design from the plan
   (Codex correction). Chip strip renders above the composer post-claim
   when ai_assessment_data.suggested_steps[] is non-empty. Click prefills
   the input and focuses; first send or explicit X hides for the session.

3. Unread 6px dot on EscalationQueue cards. localStorage-persisted seen
   set (rf-escalation-seen, capped 200). Dot top-right when not seen.
   Cleared on open (card click) or claim (Pick Up) — NOT on hover, per
   Codex correction. Pick Up stops propagation so it doesn't double-fire.

4. Race-condition toast on claim conflict. The /claim endpoint previously
   silently overwrote claimed_by — both seniors thought they owned the
   session. New HandoffAlreadyClaimedError carries the winner's id/name/
   timestamp; claim_session rejects different-user re-claims (same-user is
   idempotent for double-click safety); endpoint returns 409 with
   structured detail. AssistantChatPage.handleStartHere extracts and
   surfaces "Already claimed by {name} {time_ago}." via toast, drops
   ?pickup=true, dismisses magic-moment so the loser flows back to queue.

Tests: 2 new unit tests in test_handoff_manager.py (conflict raises,
same-user idempotent). Full handoff + escalation suite (34 tests) green.
Frontend tsc -b clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/flowpilot/EscalationQueue.tsx

@@ -26,6 +26,34 @@ const sortNewestFirst = (a: AISessionSummary, b: AISessionSummary) =>
 // state transition.
 const NEW_CARD_HIGHLIGHT_MS = 800
 
+// localStorage key for the per-user "seen" set. Tracks session IDs the user
+// has acknowledged so the unread dot doesn't reappear on refresh. Bounded to
+// the last `SEEN_CAP` entries to avoid unbounded growth on long-lived
+// accounts.
+const SEEN_STORAGE_KEY = 'rf-escalation-seen'
+const SEEN_CAP = 200
+
+function loadSeenIds(): Set<string> {
+  try {
+    const raw = localStorage.getItem(SEEN_STORAGE_KEY)
+    if (!raw) return new Set()
+    const parsed = JSON.parse(raw) as unknown
+    if (!Array.isArray(parsed)) return new Set()
+    return new Set(parsed.filter((v): v is string => typeof v === 'string'))
+  } catch {
+    return new Set()
+  }
+}
+
+function saveSeenIds(ids: Set<string>): void {
+  try {
+    const arr = Array.from(ids).slice(-SEEN_CAP)
+    localStorage.setItem(SEEN_STORAGE_KEY, JSON.stringify(arr))
+  } catch {
+    // localStorage unavailable / quota — silent. The dot just won't persist.
+  }
+}
+
 function waitTimeColor(createdAt: string): string {
   const hours = (Date.now() - new Date(createdAt).getTime()) / 3_600_000
   if (hours >= 4) return '#f87171'   // danger
@@ -42,6 +70,20 @@ export function EscalationQueue({ onPickup, onCountChange }: EscalationQueueProp
   const [newIds, setNewIds] = useState<Set<string>>(new Set())
   // Track count of unseen arrivals while the tab is backgrounded.
   const [unseenCount, setUnseenCount] = useState(0)
+  // Per-user seen set persisted in localStorage. Cleared on open, claim, or
+  // explicit dismiss (NOT on hover — Codex correction). The unread dot is
+  // shown for any session id NOT in this set.
+  const [seenIds, setSeenIds] = useState<Set<string>>(() => loadSeenIds())
+
+  const markSeen = useCallback((sessionId: string) => {
+    setSeenIds(prev => {
+      if (prev.has(sessionId)) return prev
+      const next = new Set(prev)
+      next.add(sessionId)
+      saveSeenIds(next)
+      return next
+    })
+  }, [])
 
   // Ref mirrors the latest sessions so the SSE handler can diff without
   // re-binding on every state change.
@@ -190,6 +232,7 @@ export function EscalationQueue({ onPickup, onCountChange }: EscalationQueueProp
   }, [handleHandoffCreated])
 
   const handlePickup = (sessionId: string) => {
+    markSeen(sessionId)
     if (onPickup) {
       onPickup(sessionId)
     } else {
@@ -197,6 +240,14 @@ export function EscalationQueue({ onPickup, onCountChange }: EscalationQueueProp
     }
   }
 
+  // Click on the card body (anywhere outside Pick Up) marks the session as
+  // seen — the "open" affordance from the unread-dot spec. Pick Up handles
+  // its own marking via handlePickup. Hover deliberately does NOT clear
+  // (Codex correction).
+  const handleCardOpen = (sessionId: string) => {
+    markSeen(sessionId)
+  }
+
   if (isLoading) {
     return (
       <div className="flex items-center justify-center py-12">
@@ -256,15 +307,26 @@ export function EscalationQueue({ onPickup, onCountChange }: EscalationQueueProp
       <div role="region" aria-live="polite" className="space-y-3">
         {sessions.map((session) => {
           const isNew = newIds.has(session.id)
+          const isUnread = !seenIds.has(session.id)
           return (
             <div
               key={session.id}
+              onClick={() => handleCardOpen(session.id)}
               className={cn(
-                'card-flat p-3 sm:p-4 space-y-3',
+                'relative card-flat p-3 sm:p-4 space-y-3 cursor-pointer',
                 isNew && !prefersReducedMotion && 'animate-slide-in-bottom',
                 isNew && prefersReducedMotion && 'animate-fade-in',
               )}
             >
+              {/* Unread indicator: 6px dot, top-right corner. Cleared on
+                  open (card click) or claim (Pick Up). Persists across
+                  refresh via localStorage. */}
+              {isUnread && (
+                <span
+                  aria-label="Unread escalation"
+                  className="absolute top-2 right-2 inline-block w-1.5 h-1.5 rounded-full bg-accent"
+                />
+              )}
               <div>
                 <p className="text-sm font-semibold text-foreground">
                   {session.problem_summary || 'Untitled session'}
@@ -303,7 +365,10 @@ export function EscalationQueue({ onPickup, onCountChange }: EscalationQueueProp
 
               <div className="flex justify-end">
                 <button
-                  onClick={() => handlePickup(session.id)}
+                  onClick={(e) => {
+                    e.stopPropagation()
+                    handlePickup(session.id)
+                  }}
                   className="rounded-lg bg-primary text-white px-4 py-2.5 text-sm font-semibold hover:brightness-110 active:scale-[0.98] transition-all"
                 >
                   Pick Up