Merge remote-tracking branch 'gitea/develop' into feat/501-mcp-apikey-auth

.env.example

@@ -312,6 +312,16 @@ MCP_DOCMOST_PASSWORD=
 # enabled for a workspace, and the same single-instance constraint applies (the
 # registry is process-local).
 # AI_CHAT_RESUMABLE_STREAM=false
+#
+# Per-run replay ring cap (#491), in BYTES, for the resumable-stream registry
+# above. The registry buffers the run's recent SSE tail so a reopened tab can
+# attach and continue from the step it already persisted; the ring is bounded and
+# rotates on every confirmed step-persist. This caps the un-persisted tail between
+# rotations — an overflow evicts the oldest frames and a late attach falls back to
+# 204 -> degraded poll, so correctness never depends on the size. Default 4194304
+# (4MB); a 0/invalid value falls back to the default. The per-subscriber backpressure
+# cap is derived as 2x this value. Only meaningful with AI_CHAT_RESUMABLE_STREAM on.
+# AI_CHAT_RUN_STREAM_MAX_BUFFER_BYTES=4194304
 
 # --- Run lifecycle tunables (#487) ---
 # These govern the universal run machinery (every turn is now a first-class run,