feat: [US-034] - Save project to database

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/components/editor/Toolbar.tsx

@@ -7,6 +7,7 @@ type ToolbarProps = {
   onSave: () => void
   onExport: () => void
   onImport: () => void
+  isSaving?: boolean
 }
 
 export default function Toolbar({
@@ -16,6 +17,7 @@ export default function Toolbar({
   onSave,
   onExport,
   onImport,
+  isSaving = false,
 }: ToolbarProps) {
   return (
     <div className="flex items-center justify-between border-b border-zinc-200 bg-zinc-50 px-4 py-2 dark:border-zinc-700 dark:bg-zinc-800">
@@ -46,9 +48,32 @@ export default function Toolbar({
       <div className="flex items-center gap-2">
         <button
           onClick={onSave}
-          className="rounded border border-zinc-300 bg-white px-3 py-1.5 text-sm font-medium text-zinc-700 hover:bg-zinc-50 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 dark:border-zinc-600 dark:bg-zinc-700 dark:text-zinc-200 dark:hover:bg-zinc-600 dark:focus:ring-offset-zinc-800"
+          disabled={isSaving}
+          className="flex items-center gap-1.5 rounded border border-zinc-300 bg-white px-3 py-1.5 text-sm font-medium text-zinc-700 hover:bg-zinc-50 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50 dark:border-zinc-600 dark:bg-zinc-700 dark:text-zinc-200 dark:hover:bg-zinc-600 dark:focus:ring-offset-zinc-800"
         >
-          Save
+          {isSaving && (
+            <svg
+              className="h-4 w-4 animate-spin"
+              xmlns="http://www.w3.org/2000/svg"
+              fill="none"
+              viewBox="0 0 24 24"
+            >
+              <circle
+                className="opacity-25"
+                cx="12"
+                cy="12"
+                r="10"
+                stroke="currentColor"
+                strokeWidth="4"
+              />
+              <path
+                className="opacity-75"
+                fill="currentColor"
+                d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
+              />
+            </svg>
+          )}
+          {isSaving ? 'Saving...' : 'Save'}
         </button>
         <button
           onClick={onExport}