docs(server-changes): document mollifier API GET read-fallback

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: d-cs

.server-changes/mollifier-reads.md

@@ -0,0 +1,7 @@
+---
+area: webapp
+type: feature
+---
+
+Mollifier API GET read-fallback: serve buffered runs from synthetic run, trace, and span primitives so the retrieve, trace, spans, and attempts API endpoints return parity data before a run is drained.
+</content>