chore: add changeset for closeAndFlush fix

Author: MichaelGHSeg

.changeset/closeandflush-abort-fix.md

@@ -0,0 +1,9 @@
+---
+'@segment/analytics-node': patch
+---
+
+Fix closeAndFlush silently dropping in-flight events on timeout.
+
+- Cancel pending retry sleeps via AbortController when closeAndFlush times out, instead of silently swallowing the timeout error.
+- Raise default closeAndFlush timeout floor to 75s (was 12.5s) so it survives at least one Retry-After: 60 cycle.
+- Add `http_response` emitter event for observing API response status codes and headers.