Bump version string to 3.0.0-beta

frontend/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "mempool-frontend",
-  "version": "3.0.0-dev",
+  "version": "3.0.0-beta",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "mempool-frontend",
-      "version": "3.0.0-dev",
+      "version": "3.0.0-beta",
       "license": "GNU Affero General Public License v3.0",
       "dependencies": {
         "@angular-devkit/build-angular": "^17.3.1",