Stop macOS agent updates from spawning BTM entries

Unsigned darwin release tarballs replaced the Developer ID
binary on each auto-update, so Background Task Management
treated every release as a new identity and showed the generic
executable icon. Sign those archives with a stable identifier,
refuse signature downgrades, and attribute daemon/tray jobs to
Probo Agent.app via AssociatedBundleIdentifiers.

Signed-off-by: Ludovic Vielle <ludovic@probo.com>

pkg/deviceagent/tray/launchagent.plist.tmpl

@@ -16,5 +16,9 @@
     <true/>
     <key>KeepAlive</key>
     <true/>
+    <key>AssociatedBundleIdentifiers</key>
+    <array>
+        <string>com.probo.agent.url-handler</string>
+    </array>
 </dict>
 </plist>