ui: the tour names the dock button; the user guide's key table follows shortcuts.cpp

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

src/ui_app.hpp

@@ -786,8 +786,8 @@ struct App {
   std::string config_comment;
   /// The cache of captured events, and whether latches are being written to it. The store is created
   /// once the source is known (it is keyed on `<host>-<port>`, like the packet capture);
-  /// `event_recording` is the trigger panel's switch and defaults on -- the cache is only useful if
-  /// it was already on when the event you wanted happened.
+  /// `event_recording` is the trigger panel's switch and starts off; the cache is only useful if
+  /// it was already on when the event you wanted happened, so switch it on before the events you want.
   std::unique_ptr<EventStore> event_store;
   /// Whether the cache holds anything, refreshed once a second: what keeps the dock's Events block and the
   /// `events` page live for a source whose events are already written, even with recording switched off.