river: implement xdg-activation-v1

- add a new "urgent" border color
- add a new event to river-status-unstable-v1

Co-authored-by: Isaac Freund <ifreund@ifreund.xyz>

protocol/river-status-unstable-v1.xml

@@ -16,7 +16,7 @@
     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   </copyright>
 
-  <interface name="zriver_status_manager_v1" version="1">
+  <interface name="zriver_status_manager_v1" version="2">
     <description summary="manage river status objects">
       A global factory for objects that receive status information specific
       to river. It could be used to implement, for example, a status bar.
@@ -47,7 +47,7 @@
     </request>
   </interface>
 
-  <interface name="zriver_output_status_v1" version="1">
+  <interface name="zriver_output_status_v1" version="2">
     <description summary="track output tags and focus">
       This interface allows clients to receive information about the current
       windowing state of an output.
@@ -75,6 +75,14 @@
       </description>
       <arg name="tags" type="array" summary="array of 32-bit bitfields"/>
     </event>
+
+    <event name="urgent_tags" since="2">
+      <description summary="tags of the output with an urgent view">
+        Sent once on binding the interface and again whenever the set of
+        tags with at least one urgent view changes.
+      </description>
+      <arg name="tags" type="uint" summary="32-bit bitfield"/>
+    </event>
   </interface>
 
   <interface name="zriver_seat_status_v1" version="1">