fix(landing): restore SandboxWorkspacePermissionsProvider for the capture harness

Staging removed the sandbox provider as unused when the academy pages were
deleted (#5388), but the landing-preview capture route committed on this
branch imports it - the branch failed to compile after rebasing. Restore the
lightweight provider with its consumer documented.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: andresdjasso

apps/sim/app/workspace/[workspaceId]/providers/workspace-permissions-provider.tsx

@@ -245,3 +245,36 @@ export function useUserPermissionsContext(): WorkspaceUserPermissions & {
   const { userPermissions } = useWorkspacePermissionsContext()
   return userPermissions
 }
+
+/**
+ * Lightweight permissions provider for sandbox/capture contexts (the
+ * landing-preview capture harness). Grants full edit access without any API
+ * calls or workspace dependencies.
+ */
+export function SandboxWorkspacePermissionsProvider({ children }: { children: React.ReactNode }) {
+  const sandboxPermissions = useMemo(
+    (): WorkspacePermissionsContextType => ({
+      workspacePermissions: null,
+      permissionsLoading: false,
+      permissionsError: null,
+      updatePermissions: () => {},
+      refetchPermissions: async () => {},
+      userPermissions: {
+        canRead: true,
+        canEdit: true,
+        canAdmin: false,
+        userPermissions: 'write',
+        isLoading: false,
+        error: null,
+        isOfflineMode: false,
+      },
+    }),
+    []
+  )
+
+  return (
+    <WorkspacePermissionsContext.Provider value={sandboxPermissions}>
+      {children}
+    </WorkspacePermissionsContext.Provider>
+  )
+}