ui: one badge per enabled signal, an N signals overflow, and the order kept in memory

docs/claude/probe-readings.md

@@ -2652,6 +2652,20 @@ the slide-over closed and the page was dropped by `signal_pages_sync()`. `pruned
 channel removed) and the slide-over was still on `trigger`, both by `slideover_page()` and by the stack's visible child; `0` is `signal_pages_sync()` parking the stack on the
 signals list while the title and the badge marker still name `trigger`; `-1` when there is no `trigger` page or no math channel could be added.
 
+## `[sigbadges]`
+
+```
+[sigbadges] enabled=4 badges=4 overflow=0 overflow_text=- plus_visible=1 dot_plotted=4 bar_h=36 bar_h_fixed=1 bar_min_w=336 opens=1 plus_opens=1
+```
+
+`UDPSCOPE_PROBE_SIGNAL_BADGES_MS` reads the signal badges. `badges` must equal `enabled` (the enabled, listed signals) while `enabled` is at most 6
+(`kMaxSignalBadges`); beyond that `badges=0 overflow=1 overflow_text=<N> signals plus_visible=0` (the "N signals" badge replaces the badges and the "+"). `dot_plotted` is the number of
+badges whose signal is on a plot (its dot is then the trace colour, not the unplotted grey). `bar_h` is the bar's allocated height and `bar_h_fixed=1` that neither it nor its natural
+height moved while one signal was switched off and on again (`rebuild_signal_panels()` each time), and that the badge count followed; `0` is a bar whose height depends on its content.
+`bar_min_w` is only a record: the scroller must keep it the same however many signals there are (it reads 336 with the mock's 4 and with the overflow forced on). `opens=1`: clicking the
+first signal badge opens `signal:<name>` with the badge marked open and a second click closes it (`-1` when overflowed, there being no signal badges); `plus_opens=1` the same for the "+"
+(the overflow badge when overflowed) and the `signals` page.
+
 ## `[badges]`
 
 ```