improved perfs and event management

docs/claude/verification.md

@@ -26,6 +26,12 @@ all. A fifth warning, or any critical, is a finding.
 An *incremental* build reads **two** of those four: the generated GResource `.c` files are not
 recompiled when only `src/` changed, so their `-Woverlength-strings` do not reappear.
 
+A third reading every run offers for free: **how many `[udpscope] buffer allocated:` lines it
+printed.** The line is not behind a probe — it is in every build — and one line is one *real* change
+of buffer plan, each of which blocks the main thread for the time it takes to touch the whole
+`--buffer-mb`. A normal run prints two or three. Fifteen at startup is the defect it was added for;
+see [probe-readings.md](probe-readings.md).
+
 That second baseline used to be "exactly two, `gtk_widget_get_height` and `gtk_widget_get_width`,
 from the dump asking a destroyed widget for its size", and tolerating them was a mistake: the dump
 runs from the destroy handler, so the widget pointer is **freed memory**, and a critical is only