Display HTTP Actions URL in dashboard (#25611)

![Screenshot 2024-05-13 at 11 49 59 AM](https://github.com/get-convex/convex/assets/4319355/75b5995f-4392-450c-8fcb-66c63853d3dc)
![Screenshot 2024-05-13 at 11 49 00 AM](https://github.com/get-convex/convex/assets/4319355/9f60f48a-3efa-4ca3-b493-16baab7e3d07)
![Screenshot 2024-05-13 at 11 48 42 AM](https://github.com/get-convex/convex/assets/4319355/e057253c-18c0-4847-9e6a-183fb03c76aa)

GitOrigin-RevId: 506bff2c9f0b88ac61ffdfdd539b48740faa5305

Author: ldanilek

npm-packages/system-udfs/convex/_generated/api.d.ts

@@ -23,6 +23,7 @@ import type * as _system_cli_tables from "../_system/cli/tables.js";
 import type * as _system_frontend_addDocument from "../_system/frontend/addDocument.js";
 import type * as _system_frontend_clearTablePage from "../_system/frontend/clearTablePage.js";
 import type * as _system_frontend_common from "../_system/frontend/common.js";
+import type * as _system_frontend_convexSiteUrl from "../_system/frontend/convexSiteUrl.js";
 import type * as _system_frontend_createTable from "../_system/frontend/createTable.js";
 import type * as _system_frontend_deleteDocuments from "../_system/frontend/deleteDocuments.js";
 import type * as _system_frontend_deploymentState from "../_system/frontend/deploymentState.js";
@@ -73,6 +74,7 @@ declare const fullApi: ApiFromModules<{
   "_system/frontend/addDocument": typeof _system_frontend_addDocument;
   "_system/frontend/clearTablePage": typeof _system_frontend_clearTablePage;
   "_system/frontend/common": typeof _system_frontend_common;
+  "_system/frontend/convexSiteUrl": typeof _system_frontend_convexSiteUrl;
   "_system/frontend/createTable": typeof _system_frontend_createTable;
   "_system/frontend/deleteDocuments": typeof _system_frontend_deleteDocuments;
   "_system/frontend/deploymentState": typeof _system_frontend_deploymentState;

npm-packages/system-udfs/convex/_system/frontend/convexSiteUrl.ts

@@ -0,0 +1,10 @@
+import { queryPrivateSystem } from "../secretSystemTables";
+
+declare const process: { env: { CONVEX_SITE_URL: string } };
+
+export default queryPrivateSystem({
+  args: {},
+  handler: async function () {
+    return process.env.CONVEX_SITE_URL;
+  },
+});