[launchd] Add snapclient plist

launchd/Library/LaunchAgents/com.snapcast.snapclient.plist

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
+  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>Label</key>
+    <string>com.snapcast.snapclient</string>
+
+    <key>ProgramArguments</key>
+    <array>
+        <string>/opt/homebrew/bin/snapclient</string>
+        <string>-h</string>
+        <string>snapcast.service</string>
+    </array>
+
+    <key>RunAtLoad</key>
+    <true/>
+
+    <key>KeepAlive</key>
+    <true/>
+
+    <key>StandardOutPath</key>
+    <string>/tmp/snapclient.out</string>
+
+    <key>StandardErrorPath</key>
+    <string>/tmp/snapclient.err</string>
+</dict>
+</plist>