feat(app): новый визуальный язык, верхняя навигация, портфели, создание счетов и ручные события

Тема и общие виджеты (AssetIcon, ServiceMark, HelpTip, глоссарий), верхняя панель TopNav и вкладки Аналитики вместо NavSidebar, иконки PWA. Экраны: портфели, создание брокерского счёта, ручное событие, правка инструмента, Обзор карточками по скоупам и таблица активов, пересчёт метрик с опросом /metrics/status. design-system.md обновлён.

app/lib/core/widgets/section_card.dart

@@ -1,9 +1,17 @@
 import 'package:flutter/material.dart';
 
+import 'help_tip.dart';
+
 /// A titled card section, the layout unit the phase-4 screens are built from (the same
 /// shape Портфель already uses inline).
 class SectionCard extends StatelessWidget {
-  const SectionCard({required this.title, required this.child, this.subtitle, this.trailing, super.key});
+  const SectionCard({
+    required this.title,
+    required this.child,
+    this.subtitle,
+    this.trailing,
+    super.key,
+  });
 
   final String title;
   final String? subtitle;
@@ -25,13 +33,15 @@ class SectionCard extends StatelessWidget {
                   child: Column(
                     crossAxisAlignment: CrossAxisAlignment.start,
                     children: [
-                      Text(title, style: theme.textTheme.titleMedium),
+                      TermLabel(title, style: theme.textTheme.titleMedium),
                       if (subtitle != null)
                         Padding(
                           padding: const EdgeInsets.only(top: 2),
                           child: Text(
                             subtitle!,
-                            style: theme.textTheme.bodySmall?.copyWith(color: theme.hintColor),
+                            style: theme.textTheme.bodySmall?.copyWith(
+                              color: theme.hintColor,
+                            ),
                           ),
                         ),
                     ],
@@ -51,7 +61,13 @@ class SectionCard extends StatelessWidget {
 
 /// A compact labelled number, used for the summary rows of the phase-4 screens.
 class StatTile extends StatelessWidget {
-  const StatTile({required this.label, required this.value, this.note, this.width = 184, super.key});
+  const StatTile({
+    required this.label,
+    required this.value,
+    this.note,
+    this.width = 184,
+    super.key,
+  });
 
   final String label;
   final Widget value;
@@ -69,14 +85,19 @@ class StatTile extends StatelessWidget {
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-              Text(label, style: theme.textTheme.bodySmall),
+              TermLabel(label, style: theme.textTheme.bodySmall),
               const SizedBox(height: 4),
-              DefaultTextStyle(style: theme.textTheme.titleMedium!, child: value),
+              DefaultTextStyle(
+                style: theme.textTheme.titleMedium!,
+                child: value,
+              ),
               if (note != null) ...[
                 const SizedBox(height: 2),
                 Text(
                   note!,
-                  style: theme.textTheme.bodySmall?.copyWith(color: theme.hintColor),
+                  style: theme.textTheme.bodySmall?.copyWith(
+                    color: theme.hintColor,
+                  ),
                   maxLines: 3,
                 ),
               ],