fix: replace Import button with "Save to Flow Library" and remove duplicate check

- After generation, toolbar shows "Save to Flow Library" button
  (replaces "Import to Editor")
- Button shows "Saving..." spinner state during API call
- Generate button shows animated spinner during generation
- Backend /import endpoint always creates a new Tree record
  (removed generated_tree_id idempotency check)
- Navigates to tree editor after successful save

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

backend/app/api/endpoints/ai_chat.py

@@ -387,12 +387,8 @@ async def import_tree(
             detail="Session must be completed with a generated tree before importing",
         )
 
-    if session.generated_tree_id:
-        return AIChatImportResponse(
-            tree_id=session.generated_tree_id,
-            tree_type=session.flow_type,
-        )
-
+    # Always create a new Tree record (no duplicate check — user may
+    # want multiple copies or re-import after edits)
     metadata = session.tree_metadata or {}
     tree = Tree(
         name=data.name or metadata.get("name", "AI-Generated Flow"),

frontend/src/components/ai-chat/ChatToolbar.tsx

@@ -1,4 +1,4 @@
-import { Sparkles, Download, RotateCcw, ArrowRight } from 'lucide-react'
+import { Sparkles, Save, RotateCcw, Loader2 } from 'lucide-react'
 import { PhaseIndicator } from './PhaseIndicator'
 import { cn } from '@/lib/utils'
 import type { InterviewPhase } from '@/types'
@@ -8,8 +8,9 @@ interface ChatToolbarProps {
   status: 'idle' | 'active' | 'completed' | 'abandoned'
   isGenerating: boolean
   hasGeneratedTree: boolean
+  isSaving: boolean
   onGenerate: () => void
-  onImport: () => void
+  onSave: () => void
   onReset: () => void
 }
 
@@ -18,8 +19,9 @@ export function ChatToolbar({
   status,
   isGenerating,
   hasGeneratedTree,
+  isSaving,
   onGenerate,
-  onImport,
+  onSave,
   onReset,
 }: ChatToolbarProps) {
   return (
@@ -44,22 +46,42 @@ export function ChatToolbar({
               'disabled:opacity-50 disabled:cursor-not-allowed'
             )}
           >
-            <Download className="h-3.5 w-3.5" />
-            {isGenerating ? 'Generating...' : 'Generate Flow'}
+            {isGenerating ? (
+              <>
+                <Loader2 className="h-3.5 w-3.5 animate-spin" />
+                Generating...
+              </>
+            ) : (
+              <>
+                <Sparkles className="h-3.5 w-3.5" />
+                Generate Flow
+              </>
+            )}
           </button>
         )}
 
         {hasGeneratedTree && (
           <button
-            onClick={onImport}
+            onClick={onSave}
+            disabled={isSaving}
             className={cn(
               'flex items-center gap-1.5 rounded-lg px-3 py-1.5 text-sm font-medium',
               'bg-gradient-brand text-white shadow-lg shadow-primary/20',
-              'hover:opacity-90 transition-opacity'
+              'hover:opacity-90 transition-opacity',
+              'disabled:opacity-50 disabled:cursor-not-allowed'
             )}
           >
-            <ArrowRight className="h-3.5 w-3.5" />
-            Import to Editor
+            {isSaving ? (
+              <>
+                <Loader2 className="h-3.5 w-3.5 animate-spin" />
+                Saving...
+              </>
+            ) : (
+              <>
+                <Save className="h-3.5 w-3.5" />
+                Save to Flow Library
+              </>
+            )}
           </button>
         )}
 

frontend/src/pages/AIChatBuilderPage.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect } from 'react'
+import { useCallback, useEffect, useState } from 'react'
 import { useNavigate, useSearchParams } from 'react-router-dom'
 import { useAIChatStore } from '@/store/aiChatStore'
 import { ChatPanel } from '@/components/ai-chat/ChatPanel'
@@ -62,11 +62,15 @@ export function AIChatBuilderPage() {
     [sendMessage]
   )
 
+  const [isSaving, setIsSaving] = useState(false)
+
   const handleGenerate = useCallback(() => {
     generateTree()
   }, [generateTree])
 
-  const handleImport = useCallback(async () => {
+  const handleSave = useCallback(async () => {
+    if (isSaving) return
+    setIsSaving(true)
     try {
       const treeId = await importToEditor({
         name: treeMetadata?.name,
@@ -75,11 +79,13 @@ export function AIChatBuilderPage() {
       })
       const path = getTreeEditorPath(treeId, flowType)
       navigate(path)
-      toast.success('Flow imported to editor')
+      toast.success('Flow saved to library')
     } catch {
-      toast.error('Failed to import flow')
+      toast.error('Failed to save flow')
+    } finally {
+      setIsSaving(false)
     }
-  }, [importToEditor, treeMetadata, flowType, navigate])
+  }, [isSaving, importToEditor, treeMetadata, flowType, navigate])
 
   const handleReset = useCallback(async () => {
     await abandonSession()
@@ -116,8 +122,9 @@ export function AIChatBuilderPage() {
         status={status}
         isGenerating={isGenerating}
         hasGeneratedTree={!!generatedTree}
+        isSaving={isSaving}
         onGenerate={handleGenerate}
-        onImport={handleImport}
+        onSave={handleSave}
         onReset={handleReset}
       />