step7: live BandConfig capture infra + FUN_180563a60 decode — GUI-only, audio path refutes premise (22b)

play.lua

@@ -1,10 +1,17 @@
 -- play.lua : realtime transport playback to keep the DSP host's audio callback
 -- alive, so an external script can snapshot memory while ctx fields are live.
+-- NOTE: reaper.Sleep does not exist in the REAPER API; use reaper.defer loop.
 local keep_secs = 300
 
 reaper.Main_OnCommand(1007, 0)  -- Transport: Play (realtime audio)
 local t0 = reaper.time_precise()
-while reaper.time_precise() - t0 < keep_secs do
-    reaper.Sleep(200)
+
+local function keepalive()
+  if reaper.time_precise() - t0 < keep_secs then
+    reaper.defer(keepalive)      -- yield; runs on every UI update tick
+  else
+    reaper.OnStopButton()
+  end
 end
-reaper.OnStopButton()
+
+reaper.defer(keepalive)