feat(ui): Flows page (5th destination) + keyboard shortcuts

Two operator-DX additions:

1. **Flows** is the new third destination in the sidebar.
   Lists saved flows from the hub via the new HubAdmin
   ListFlows RPC. Each row has a Run button that opens an
   input dialog (key=value pairs, one per line, all values
   sent as text payloads — the binary-input case stays in
   `fai run` CLI). Flow runs in a non-dismissable progress
   dialog; output is shown per-key with monospace
   selectable text. Errors render with the exception detail
   for diagnosis.

2. **Keyboard shortcuts** at the shell level:
   - Cmd+1 / Cmd+2 / Cmd+3 / Cmd+4 / Cmd+5 jump to the
     matching destination (Doctor / Modules / Flows / Audit
     / Approvals).
   - Cmd+, opens the Settings dialog (macOS convention).

   Implemented via Flutter's Shortcuts/Actions/Intent triple
   so the bindings are discoverable in IDE devtools and
   composable with platform-specific overrides later.

Bumps fai_studio 0.7.3 -> 0.8.0.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/main.dart

@@ -7,10 +7,13 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 
+import 'package:flutter/services.dart';
+
 import 'data/hub.dart';
 import 'pages/approvals.dart';
 import 'pages/audit.dart';
 import 'pages/doctor.dart';
+import 'pages/flows.dart';
 import 'pages/modules.dart';
 import 'theme/theme.dart';
 import 'theme/tokens.dart';
@@ -19,7 +22,7 @@ import 'widgets/widgets.dart';
 /// Studio's own build version. Bump on every UI commit so the
 /// running app self-identifies — visible in the sidebar header
 /// and quick-glance proof that you're seeing the current build.
-const String kStudioVersion = '0.7.3';
+const String kStudioVersion = '0.8.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -121,6 +124,12 @@ class _StudioShellState extends State<StudioShell> {
       selectedIcon: Icons.extension,
       page: ModulesPage(),
     ),
+    _NavPage(
+      label: 'Flows',
+      icon: Icons.account_tree_outlined,
+      selectedIcon: Icons.account_tree,
+      page: FlowsPage(),
+    ),
     _NavPage(
       label: 'Audit',
       icon: Icons.timeline_outlined,
@@ -160,22 +169,52 @@ class _StudioShellState extends State<StudioShell> {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
-    return Scaffold(
-      body: Row(
-        children: [
-          _Sidebar(
-            selectedIndex: _selectedIndex,
-            onSelect: (i) => setState(() => _selectedIndex = i),
-            pages: _pages,
-            connected: _connected,
-            endpointLabel: HubService.instance.endpointLabel,
+    return Shortcuts(
+      shortcuts: <ShortcutActivator, Intent>{
+        // Cmd+1..5 jumps to the matching destination. Numbered
+        // 1-based to match the visual order in the sidebar.
+        for (var i = 0; i < _pages.length; i++)
+          SingleActivator(
+            LogicalKeyboardKey(LogicalKeyboardKey.digit1.keyId + i),
+            meta: true,
+          ): _GoToPageIntent(i),
+        // Cmd+, opens the settings dialog (macOS convention).
+        const SingleActivator(LogicalKeyboardKey.comma, meta: true):
+            const _OpenSettingsIntent(),
+      },
+      child: Actions(
+        actions: <Type, Action<Intent>>{
+          _GoToPageIntent: CallbackAction<_GoToPageIntent>(
+            onInvoke: (intent) {
+              setState(() => _selectedIndex = intent.index);
+              return null;
+            },
           ),
-          Container(
-            width: 1,
-            color: theme.colorScheme.outlineVariant,
+          _OpenSettingsIntent: CallbackAction<_OpenSettingsIntent>(
+            onInvoke: (_) {
+              FaiSettingsDialog.show(context);
+              return null;
+            },
           ),
-          Expanded(
-            child: AnimatedSwitcher(
+        },
+        child: Focus(
+          autofocus: true,
+          child: Scaffold(
+            body: Row(
+              children: [
+                _Sidebar(
+                  selectedIndex: _selectedIndex,
+                  onSelect: (i) => setState(() => _selectedIndex = i),
+                  pages: _pages,
+                  connected: _connected,
+                  endpointLabel: HubService.instance.endpointLabel,
+                ),
+                Container(
+                  width: 1,
+                  color: theme.colorScheme.outlineVariant,
+                ),
+                Expanded(
+                  child: AnimatedSwitcher(
               duration: FaiMotion.base,
               switchInCurve: FaiMotion.easing,
               switchOutCurve: FaiMotion.easing,
@@ -189,18 +228,31 @@ class _StudioShellState extends State<StudioShell> {
                   child: child,
                 ),
               ),
-              child: KeyedSubtree(
-                key: ValueKey(_selectedIndex),
-                child: _pages[_selectedIndex].page,
-              ),
+                    child: KeyedSubtree(
+                      key: ValueKey(_selectedIndex),
+                      child: _pages[_selectedIndex].page,
+                    ),
+                  ),
+                ),
+              ],
             ),
           ),
-        ],
+        ),
       ),
     );
   }
 }
 
+/// Intents driven by the Shortcuts/Actions pair on the shell.
+class _GoToPageIntent extends Intent {
+  final int index;
+  const _GoToPageIntent(this.index);
+}
+
+class _OpenSettingsIntent extends Intent {
+  const _OpenSettingsIntent();
+}
+
 class _Sidebar extends StatelessWidget {
   final int selectedIndex;
   final ValueChanged<int> onSelect;