The refusal was never silent -- `on_drop_channel()` has always set a notice -- but the
status bar renders `notice + " | " + glance` in one label, so "plot 1 already holds
four signals" arrived looking like part of the routine text a reader skims, which is the
"no clear user feedback" report. The probe's own reading showed it plainly: the label held
`plotting 'sine' on plot 1 | live · 4.44 kS/s · 2 s window`.
Three changes:
- While a notice is fresh the status label carries the stock `.warning` class, so a message
looks like a message and the class goes when the notice does. Every notice benefits, not
just this one.
- The refusal says what to *do*: "plot 1 holds four signals already: drop it on another
plot, or add a row with the layout editor (L)".
- The drop's inline notice now goes through `set_notice()`, the one setter, instead of
writing `app.notice` and its deadline by hand.
[drop-probe] reads the whole path, with the row filled first so the drop under test is the
refusal:
full row refused the drop: 0 (want 0)
refused feedback: notice='plot 1 holds four signals already: ...' warning=1
the status line, composed: warning=1 status='plot 1 holds four signals already: ... | live · 9.97 kS/s · 2 s window'
The label is read in the third line and not the second on purpose: the status line composes
the notice into itself on its own cadence, so a beat after the refusal it may still hold the
previous text -- which the first attempt at this reading mistook for the fix not working.
The row limit is not silent in the same way: the layout editor's `+` is insensitive at
`kMaxRows`, which is a control that says "no" by being unusable rather than a message.
Martino Ferrari
aaf544be1e