ui: tour and help follow the readouts dock

The dock tour stop describes the read-only readouts and their Edit buttons, and the cursors and measures hints point to the dock copy and the pages.

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

src/ui_context_help.cpp

@@ -63,6 +63,10 @@ struct HelpHint {
 
 /// The table, which is the whole of the curation: a new surface is a row, and the heading row it
 /// names must already exist in `App` (that is what `ui_app.hpp`'s help-layer fields are for).
+///
+/// The trigger, cursors, measurements and signals headings live on slide-over pages, which exist
+/// (unmapped) whether or not the page is open: their hints are attached all the time and drawn while
+/// the page is on screen, so the dock needs no hint of its own and the layer has one code path.
 constexpr HelpHint kHelpHints[] = {
     {"plot", "The plot",
      "Every signal you have switched on is drawn here, one row per group of traces, with all rows "
@@ -77,12 +81,12 @@ constexpr HelpHint kHelpHints[] = {
     {"cursors", "The cursors",
      "Two movable instruments read against the window on screen: two verticals for time, two "
      "horizontals for the value axis, or the two crossings of each trace. What every plotted row "
-     "reads at the cursor is listed in this pane.",
+     "reads at the cursor is listed in this page; the dock keeps a read-only copy.",
      "C", &App::cursors_head},
     {"measures", "The measurements",
      "Readings over the visible window: average, RMS, top, peak to peak, amplitude, frequency, a "
      "threshold count and more. Statistics under a reading track how it has varied since the last "
-     "reset, without the plot having to be still.",
+     "reset, without the plot having to be still. The dock lists the values; Edit opens this page.",
      "", &App::measures_head},
     {"math", "Math channels",
      "A channel computed from the streamed ones in a small node graph: sources, gains, filters and "

src/ui_tour.cpp

@@ -39,12 +39,12 @@ namespace ui_impl {
 namespace {
 
 /// The card's width. Wide enough for a comfortable line of the paragraph, narrow enough to fit
-/// beside the plot on the documented window -- at 756 px the dock is 320 and a card wider than
+/// beside the plot on the documented window -- at 756 px the dock is 280 and a card wider than
 /// that is a card that has to cover its own target. It is a *floor* on the box, not a cap on the
 /// paragraph: the wrapped label is capped by `max_width_chars` so the natural width never exceeds it.
 constexpr int kCardWidth = 280;
 /// The gap between the hole and whatever is placed beside it. Eight and not twelve: the dock
-/// is 320 px, and it has to hold the card and both gaps.
+/// is 280 px, and it has to hold the card and both gaps.
 constexpr int kGap = 8;
 
 /// Places an overlay child of the tour overlay at an exact rectangle. `GtkOverlay` positions an
@@ -455,8 +455,10 @@ constexpr TourStep kTourSteps[] = {
      "the view then freezes on the first event that matches, however rare it is.",
      &App::trigger_body},
     {"side", nullptr, "The dock",
-     "The dock beside the plot: the cursors, then the measurements. The buttons in the bar above "
+     "The dock beside the plot is a read-only copy of the cursors and of every measurement, in a "
-     "show and hide it.",
+     "fixed width. Edit, beside each heading, opens that instrument's full panel over the plot; a "
+     "click on a measurement opens its dialog. The side-panel button in the bar above shows and hides "
+     "the dock.",
      &App::side_box},
     {"signals", "signals", "Adding a signal",
      "What can be added: the signals the source declares that are not acquired yet, each with the "
@@ -502,7 +504,7 @@ void start_tour(App& app) {
     app.settings.tour_seen = true;
     (void)save_settings(app.settings);
   }
-  // The main window has no page stack (the dock is one scroller): its pages are the slide-over's, and
+  // The main window has no page stack (the dock holds only the readouts): its pages are the slide-over's, and
   // the view's `on_page` hook opens one (or closes the panel for a stop with no page), replacing the
   // `page_stack` mechanism the chooser keeps.
   app.tour.on_page = tour_open_page;