feat: add rotating activity messages to generation loading state

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

frontend/src/components/ai-builder/GeneratingAnimation.tsx

@@ -1,31 +1,60 @@
 import { useEffect, useState } from 'react'
-import { Sparkles } from 'lucide-react'
+import { cn } from '@/lib/utils'
 
 const MESSAGES = [
-  'Analyzing your flow requirements...',
-  'Building decision paths...',
-  'Generating troubleshooting logic...',
-  'Crafting resolution steps...',
-  'Structuring the flow...',
-]
+  'Setting up your flow...',
+  'Building diagnostic paths...',
+  'Putting the pieces in place...',
+  'Almost there...',
+] as const
 
-export function GeneratingAnimation() {
+const MESSAGE_DURATIONS = [4000, 8000, 8000, Infinity] // ms each message shows
+
+interface GeneratingAnimationProps {
+  branchContext?: { current: number; total: number }
+}
+
+export function GeneratingAnimation({ branchContext }: GeneratingAnimationProps) {
   const [messageIndex, setMessageIndex] = useState(0)
 
+  // Reset and advance message on mount/remount
   useEffect(() => {
-    const interval = setInterval(() => {
-      setMessageIndex((prev) => (prev + 1) % MESSAGES.length)
-    }, 3000)
-    return () => clearInterval(interval)
+    setMessageIndex(0)
+    let current = 0
+
+    const advance = () => {
+      current += 1
+      if (current < MESSAGES.length - 1) {
+        setMessageIndex(current)
+        timer = setTimeout(advance, MESSAGE_DURATIONS[current])
+      } else {
+        setMessageIndex(MESSAGES.length - 1)
+      }
+    }
+
+    let timer = setTimeout(advance, MESSAGE_DURATIONS[0])
+    return () => clearTimeout(timer)
   }, [])
 
   return (
-    <div className="flex flex-col items-center justify-center gap-4 py-12">
-      <div className="relative">
-        <div className="h-12 w-12 animate-spin rounded-full border-4 border-border border-t-primary" />
-        <Sparkles className="absolute left-1/2 top-1/2 h-5 w-5 -translate-x-1/2 -translate-y-1/2 text-primary" />
-      </div>
-      <p className="text-sm text-muted-foreground animate-pulse">
+    <div className="flex flex-col items-center justify-center gap-4 py-10">
+      {/* Spinner */}
+      <div className="h-8 w-8 animate-spin rounded-full border-2 border-border border-t-primary" />
+
+      {/* Branch context (Generate All mode) */}
+      {branchContext && (
+        <p className="text-xs font-label uppercase tracking-wide text-muted-foreground">
+          Branch {branchContext.current} of {branchContext.total}
+        </p>
+      )}
+
+      {/* Rotating message */}
+      <p
+        key={messageIndex}
+        className={cn(
+          'text-sm text-muted-foreground transition-opacity duration-500',
+        )}
+      >
         {MESSAGES[messageIndex]}
       </p>
     </div>