Add OpenVPN Connect as a macOS FMA (#45174)

Add OpenVPN Connect to maintained apps: create a Homebrew input manifest
and add an apps.json entry. Add a darwin output with version 3.8.1
(installer URL, sha256) plus install/uninstall script refs that handle
quitting/relaunching and cleanup. Add frontend icon component and
register it in the icon map, and include the app icon asset. Default
category set to Productivity.

frontend/pages/SoftwarePage/components/icons/index.ts

@@ -24,6 +24,7 @@ import Nextcloud from "./Nextcloud";
 import Notepad from "./Notepad++";
 import OktaVerify from "./OktaVerify";
 import Ollama from "./Ollama";
+import OpenvpnConnect from "./OpenvpnConnect";
 import Proxifier from "./Proxifier";
 import Proxyman from "./Proxyman";
 import Putty from "./Putty";
@@ -430,6 +431,7 @@ export const SOFTWARE_NAME_TO_ICON_MAP = {
   omnigraffle: OmniGraffle,
   "omnissa horizon client": OmnissaHorizonClient,
   onedrive: OneDrive,
+  "openvpn connect": OpenvpnConnect,
   opera: Opera,
   orbstack: OrbStack,
   package: Package,