release: update appcast for v1.1.16

Author: JerryZLiu

docs/appcast.xml

@@ -3,6 +3,18 @@
   <channel>
     <title>Dayflow Updates</title>
     <language>en</language>
+    <item>
+      <title>Version 1.1.16</title>
+      <pubDate>Fri, 17 Oct 2025 09:52:27 +0000</pubDate>
+      <enclosure url="https://github.com/JerryZLiu/Dayflow/releases/download/v1.1.16/Dayflow.dmg"
+                 sparkle:version="56"
+                 sparkle:shortVersionString="1.1.16"
+                 length="27692823"
+                 type="application/octet-stream"
+                 sparkle:edSignature="vxLOfX26AJ+a4T7xmC+IcHuTz3imY7qrlbzoAMzvY21aQ3ZKRwk5knJTOnuhovxpC5W0ZEHWKWlwR4wN6ZPICg=="/>
+      <sparkle:minimumSystemVersion>13.0</sparkle:minimumSystemVersion>
+      <releaseNotesLink>https://github.com/JerryZLiu/Dayflow/releases/tag/v1.1.16</releaseNotesLink>
+    </item>
     <item>
       <title>Version 1.1.11</title>
       <pubDate>Tue, 14 Oct 2025 07:33:16 +0000</pubDate>