cloudflared: add service.

This matches the upstream implementation that's installed when you do
`cloudflared service install` but allows integration with
`brew services` (and also therefore `brew bundle`).

Author: MikeMcQuaid

Formula/c/cloudflared.rb

@@ -4,6 +4,7 @@ class Cloudflared < Formula
   url "https://github.com/cloudflare/cloudflared/archive/refs/tags/2024.11.1.tar.gz"
   sha256 "1bf729c225701f6864b31bb6c251293caa06f9f1a6e671f3326dd20c3c9719ff"
   license "Apache-2.0"
+  revision 1
   head "https://github.com/cloudflare/cloudflared.git", branch: "master"
 
   bottle do
@@ -25,6 +26,13 @@ def install
       "PREFIX=#{prefix}"
   end
 
+  service do
+    run [opt_bin/"cloudflared"]
+    keep_alive successful_exit: false
+    log_path var/"log/cloudflared.log"
+    error_log_path var/"log/cloudflared.log"
+  end
+
   test do
     help_output = shell_output("#{bin}/cloudflared help")
     assert_match "cloudflared - Cloudflare's command-line tool and agent", help_output