config: add pid client criteria

jay-config/src/_private.rs

@@ -83,6 +83,7 @@ pub enum ClientCriterionIpc {
     },
     Sandboxed,
     Uid(i32),
+    Pid(i32),
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, Hash, Eq, PartialEq)]

jay-config/src/_private/client.rs

@@ -1543,6 +1543,7 @@ impl ConfigClient {
             ClientCriterion::SandboxInstanceIdRegex(t) => string!(t, SandboxInstanceId, true),
             ClientCriterion::Sandboxed => ClientCriterionIpc::Sandboxed,
             ClientCriterion::Uid(p) => ClientCriterionIpc::Uid(p),
+            ClientCriterion::Pid(p) => ClientCriterionIpc::Pid(p),
         };
         let res = self.send_with_response(&ClientMessage::CreateClientMatcher { criterion });
         get_response!(

jay-config/src/client.rs

@@ -79,6 +79,8 @@ pub enum ClientCriterion<'a> {
     Sandboxed,
     /// Matches the user ID of the client.
     Uid(i32),
+    /// Matches the process ID of the client.
+    Pid(i32),
 }
 
 impl ClientCriterion<'_> {