add explicit test that logging captures headers for Delivery events

We already tested this functionality at reception time, but let's
also assert for delivery time.

crates/integration-tests/source.lua

@@ -27,7 +27,7 @@ kumo.on('init', function()
   kumo.configure_local_logs {
     log_dir = TEST_DIR .. '/logs',
     max_segment_duration = '1s',
-    headers = { 'X-*', 'Y-*' },
+    headers = { 'X-*', 'Y-*', 'Subject' },
   }
 
   if WEBHOOK_PORT then

crates/integration-tests/src/kumod.rs

@@ -437,10 +437,14 @@ impl KumoDaemon {
 
                 for line in text.lines() {
                     let record: JsonLogRecord = serde_json::from_str(&line)?;
-                    if record.kind == RecordType::Reception {
-                        assert!(record.headers.contains_key("X-Test1"));
-                        assert!(record.headers.contains_key("X-Another"));
-                        assert!(!record.headers.contains_key("y-something"));
+                    match record.kind {
+                        RecordType::Reception | RecordType::Delivery => {
+                            assert!(record.headers.contains_key("Subject"));
+                            assert!(record.headers.contains_key("X-Test1"));
+                            assert!(record.headers.contains_key("X-Another"));
+                            assert!(!record.headers.contains_key("y-something"));
+                        }
+                        _ => {}
                     }
                 }
             }

crates/integration-tests/src/main.rs

@@ -944,10 +944,13 @@ Ok(
         );
 
         let mut logged_headers = vec![];
+        let mut headers_delivered = vec![];
         for record in daemon.webhook.return_logs() {
+            let ordered_headers: BTreeMap<_, _> = record.headers.into_iter().collect();
             if record.kind == RecordType::Reception {
-                let ordered_headers: BTreeMap<_, _> = record.headers.into_iter().collect();
                 logged_headers.push(ordered_headers);
+            } else if record.kind == RecordType::Delivery {
+                headers_delivered.push(ordered_headers);
             }
         }
         k9::snapshot!(
@@ -961,6 +964,19 @@ Ok(
         "X-Test1": String("Test1"),
     },
 ]
+"#
+        );
+        k9::snapshot!(
+            headers_delivered,
+            r#"
+[
+    {
+        "Subject": String("Hello! This is a test"),
+        "X-Another": String("Another"),
+        "X-KumoRef": String("eyJfQF8iOiJcXF8vIiwicmVjaXBpZW50IjoicmVjaXBAZXhhbXBsZS5jb20ifQ=="),
+        "X-Test1": String("Test1"),
+    },
+]
 "#
         );