feat: lift docs state to App for persistence across view changes

Move externalDocs, fileTree, selectedPath, and currentContent state from
ApiDocViewer to App component so that docs state persists when switching
between docs and blueprint views.

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

src/App.tsx

@@ -3,6 +3,14 @@ import { FileText, Box, Plus } from 'lucide-react';
 import { ApiDocViewer } from './components/ApiDocViewer';
 import BlueprintPage from './components/blueprint/BlueprintPage';
 import { config } from './config';
+import type { DocFile } from '@/lib/types';
+
+interface ExternalDoc {
+  name: string
+  path: string
+  relativePath: string
+  content: string
+}
 
 const _origLog = console.log;
 const _origError = console.error;
@@ -28,6 +36,12 @@ function App() {
   const [docsPath, setDocsPath] = useState<string>('');
   const [showAddModal, setShowAddModal] = useState(false);
 
+  // Docs state lifted from ApiDocViewer to persist across view changes
+  const [externalDocs, setExternalDocs] = useState<ExternalDoc[]>([]);
+  const [fileTree, setFileTree] = useState<DocFile[]>([]);
+  const [selectedPath, setSelectedPath] = useState<string | undefined>(undefined);
+  const [currentContent, setCurrentContent] = useState<string>('');
+  
   useEffect(() => {
     document.title = config.projectName;
   }, []);
@@ -78,6 +92,14 @@ function App() {
             onDocsPathChange={setDocsPath}
             showAddModal={showAddModal}
             onCloseAddModal={() => setShowAddModal(false)}
+            externalDocs={externalDocs}
+            setExternalDocs={setExternalDocs}
+            fileTree={fileTree}
+            setFileTree={setFileTree}
+            selectedPath={selectedPath}
+            setSelectedPath={setSelectedPath}
+            currentContent={currentContent}
+            setCurrentContent={setCurrentContent}
           />
         ) : (
           <BlueprintPage docsPath={docsPath} />

src/components/ApiDocViewer.tsx

@@ -16,6 +16,14 @@ interface ApiDocViewerProps {
   onDocsPathChange?: (path: string) => void;
   showAddModal?: boolean;
   onCloseAddModal?: () => void;
+  externalDocs: ExternalDoc[];
+  setExternalDocs: React.Dispatch<React.SetStateAction<ExternalDoc[]>>;
+  fileTree: DocFile[];
+  setFileTree: React.Dispatch<React.SetStateAction<DocFile[]>>;
+  selectedPath: string | undefined;
+  setSelectedPath: React.Dispatch<React.SetStateAction<string | undefined>>;
+  currentContent: string;
+  setCurrentContent: React.Dispatch<React.SetStateAction<string>>;
 }
 
 const STORAGE_KEY = 'xc-docs-config';
@@ -36,14 +44,22 @@ function saveStoredConfig(docsPath: string, externalDocs: ExternalDoc[], selecte
   } catch {}
 }
 
-export const ApiDocViewer = ({ onDocsPathChange, showAddModal, onCloseAddModal }: ApiDocViewerProps) => {
+export const ApiDocViewer = ({
+  onDocsPathChange,
+  showAddModal,
+  onCloseAddModal,
+  externalDocs,
+  setExternalDocs,
+  fileTree,
+  setFileTree,
+  selectedPath,
+  setSelectedPath,
+  currentContent,
+  setCurrentContent
+}: ApiDocViewerProps) => {
   const stored = loadStoredConfig();
-  const [fileTree, setFileTree] = useState<DocFile[]>([])
-  const [selectedPath, setSelectedPath] = useState<string | undefined>(stored.selectedPath)
-  const [currentContent, setCurrentContent] = useState<string>('')
   const [showModal, setShowModal] = useState(false)
   const [docsPath, setDocsPath] = useState(stored.docsPath)
-  const [externalDocs, setExternalDocs] = useState<ExternalDoc[]>(stored.externalDocs)
   const [isLoading, setIsLoading] = useState(false)
   const [errorMsg, setErrorMsg] = useState<string | null>(null)
 
@@ -54,6 +70,7 @@ export const ApiDocViewer = ({ onDocsPathChange, showAddModal, onCloseAddModal }
     }
   }, [showAddModal])
 
+  // Auto-select first document when externalDocs and fileTree are loaded
   useEffect(() => {
     if (externalDocs.length > 0 && fileTree.length > 0 && !selectedPath) {
       const fileList = externalDocs
@@ -75,7 +92,7 @@ export const ApiDocViewer = ({ onDocsPathChange, showAddModal, onCloseAddModal }
         setCurrentContent(externalDocs.find(d => d.relativePath === targetPath)?.content || '')
       }
     }
-  }, [externalDocs, fileTree, selectedPath])
+  }, [externalDocs, fileTree, selectedPath, stored.selectedPath, setSelectedPath, setCurrentContent])
 
   useEffect(() => {
     if (docsPath && externalDocs.length > 0) {