feat(train): a recording under way above the bar on every tab, and a saved one opens its page (ADR 0030, D60)

halkyon_ui's NavigationFrame takes a status, standing above the floating
bar below medium windows and at the foot of the screen's panel from there
on. Train's RecordingBar fills it while a recording runs or waits to be
saved: its activity, moving time and distance, paused or stopped, a tap
back to it. Saving now opens the workout's page in Home's tab.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_ui/lib/src/widget/navigation_frame.dart

@@ -54,6 +54,12 @@ class const NavigationFrame({
   /// top-level screens and the actions of those below in a toolbar, never
   /// both at once (as Vaia does). The rail of wider windows stays.
   final bool hidesNavigationBar = false,
+
+  /// What stands above the bar on every tab while it matters (Train's
+  /// recording under way, as Strava's): floating above the bar below
+  /// medium windows, at the foot of the screen's panel from there on; none
+  /// while null.
+  final Widget? status,
   super.key,
 }) extends StatefulWidget {
   @override
@@ -102,7 +108,15 @@ class _NavigationFrameState() extends State<NavigationFrame> {
                 ),
             ],
           ),
-          child: widget.child,
+          child: switch (widget.status) {
+            final status? => Column(
+              children: [
+                Expanded(child: widget.child),
+                Padding(padding: const EdgeInsets.all(12), child: status),
+              ],
+            ),
+            null => widget.child,
+          },
         ),
       );
     }
@@ -142,9 +156,30 @@ class _NavigationFrameState() extends State<NavigationFrame> {
             // Without the bar, a strip as high as the system's own bar, in
             // the screen's background, keeps every screen inside clear of
             // it.
-            bottomNavigationBar: widget.hidesNavigationBar
-                ? SizedBox(height: MediaQuery.paddingOf(context).bottom)
-                : bar,
+            bottomNavigationBar: switch (widget.status) {
+              final status? => Column(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Padding(
+                    padding: const EdgeInsets.fromLTRB(
+                      FloatingNavigationBar.sideMargin,
+                      0,
+                      FloatingNavigationBar.sideMargin,
+                      FloatingNavigationBar.lift,
+                    ),
+                    child: status,
+                  ),
+                  if (widget.hidesNavigationBar)
+                    SizedBox(height: MediaQuery.paddingOf(context).bottom)
+                  else
+                    bar,
+                ],
+              ),
+              null when widget.hidesNavigationBar => SizedBox(
+                height: MediaQuery.paddingOf(context).bottom,
+              ),
+              null => bar,
+            },
           ),
         ),
       ),