Replace rollback with manual version selection and simplify updater

pikit-web/assets/api.js

@@ -53,10 +53,12 @@ export const applyRelease = () =>
   api("/api/update/apply", {
     method: "POST",
   });
-export const rollbackRelease = () =>
-  api("/api/update/rollback", {
+export const applyReleaseVersion = (version) =>
+  api("/api/update/apply_version", {
     method: "POST",
+    body: JSON.stringify({ version }),
   });
+export const listReleases = () => api("/api/update/releases");
 export const setReleaseAutoCheck = (enable) =>
   api("/api/update/auto", {
     method: "POST",