Fix FlutterRunner to load public dart files and add manual save

- Add polling mechanism to detect new files loaded into sessionStorage
- Fix issue where public dart files wouldn't load when FlutterRunner already open
- Replace auto-save with manual save button (floppy disk icon)
- Disable save for public files, only allow for secure storage files
- Add visual feedback for save status and loading states

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/components/FlutterRunner.tsx

@@ -6,7 +6,8 @@ import {
   Download,
   SidebarSimple,
   FileCode,
-  CaretDown
+  CaretDown,
+  FloppyDisk
 } from '@phosphor-icons/react'
 import Window from './Window'
 
@@ -167,32 +168,72 @@ export function FlutterRunner({ onClose, onMinimize, onMaximize, onFocus, zIndex
     }
   }, [initialCode])
 
-  // Auto-save to file every 2 seconds when code changes (only if passkey is set)
+  // Listen for new files being loaded while the component is already open
   useEffect(() => {
-    if (!passkey || !activeFileName) return
-
-    const saveTimer = setTimeout(async () => {
-      try {
-        // Save to secure data
-        await fetch('/api/data', {
-          method: 'POST',
-          headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({
-            key: passkey,
-            passkey: passkey,
-            action: 'save_file',
-            fileName: activeFileName,
-            content: code
-          })
-        })
-        setLastSaved(new Date())
-      } catch (error) {
-        console.error('Auto-save failed:', error)
+    const checkForNewFile = () => {
+      const sessionFileContent = sessionStorage.getItem('flutterFileContent')
+      const sessionFileName = sessionStorage.getItem('currentFileName')
+      const sessionPasskey = sessionStorage.getItem('currentPasskey')
+
+      if (sessionFileContent) {
+        console.log('Detected new file in session storage:', sessionFileName)
+        setCode(sessionFileContent)
+        setActiveFileName(sessionFileName || 'main.dart')
+
+        if (sessionPasskey) {
+          setPasskey(sessionPasskey)
+        }
+
+        // Update file structure
+        setFiles([{
+          id: 'root',
+          name: 'lib',
+          type: 'folder',
+          isOpen: true,
+          children: [
+            { id: 'main', name: sessionFileName || 'main.dart', type: 'file', content: sessionFileContent }
+          ]
+        }])
+
+        // Clear session storage after loading
+        sessionStorage.removeItem('flutterFileContent')
       }
-    }, 2000)
+    }
+
+    // Check every 500ms for new files
+    const interval = setInterval(checkForNewFile, 500)
 
-    return () => clearTimeout(saveTimer)
-  }, [code, passkey, activeFileName])
+    return () => clearInterval(interval)
+  }, [])
+
+  // Manual save function
+  const handleSave = async () => {
+    if (!passkey || !activeFileName) {
+      alert('Cannot save: No passkey set. This file is from public storage.')
+      return
+    }
+
+    try {
+      setLoading(true)
+      await fetch('/api/data', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          key: passkey,
+          passkey: passkey,
+          action: 'save_file',
+          fileName: activeFileName,
+          content: code
+        })
+      })
+      setLastSaved(new Date())
+    } catch (error) {
+      console.error('Save failed:', error)
+      alert('Failed to save file')
+    } finally {
+      setLoading(false)
+    }
+  }
 
   const handleDownload = () => {
     const blob = new Blob([code], { type: 'text/plain' })
@@ -248,6 +289,18 @@ export function FlutterRunner({ onClose, onMinimize, onMaximize, onFocus, zIndex
                 </div>
 
                 <div className="flex items-center gap-2">
+                  <button
+                    onClick={handleSave}
+                    disabled={!passkey || loading}
+                    className={`p-1.5 rounded transition-colors ${
+                      passkey && !loading
+                        ? 'text-blue-400 hover:text-blue-300 hover:bg-[#3e3e42]'
+                        : 'text-gray-600 cursor-not-allowed'
+                    }`}
+                    title={passkey ? "Save to Secure Storage" : "Cannot save public files"}
+                  >
+                    <FloppyDisk size={16} />
+                  </button>
                   <button
                     onClick={handleDownload}
                     className="p-1.5 text-gray-400 hover:text-white hover:bg-[#3e3e42] rounded transition-colors"