ui: the cursors and measurements panels are slide-over pages; the dock is the readouts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ui_dock.cpp

@@ -22,9 +22,10 @@ namespace ui_impl {
 namespace {
 
 /// The width, in characters, of a value cell and of a `who` / type cell. Fixed, so the dock is as wide
-/// with `--` as with `-123.456 mV`.
+/// with `--` as with `-123.456 mV`; their sum (5 + 3 x 9 characters) is what keeps the readouts inside the
+/// dock's 280 px.
 constexpr int kValueChars = 9;
-constexpr int kNameChars = 8;
+constexpr int kNameChars = 5;
 
 GtkWidget* fixed_label(const char* text, int chars, GtkAlign halign) {
   GtkWidget* l = gtk_label_new(text);