feat(ui): point help new-content indicator at the updated tabs and elements

- Replace timestamp comparison (help_last_viewed vs a hardcoded date) with
  a content-version marker (data-help-content-version) read from the
  rendered modal markup, so badge state always reflects the content
  actually served
- Only mark content as viewed when the modal is opened while it contains
  new content; opening a stale pre-upgrade page no longer suppresses the
  badge after a refresh
- Flag the Replay Tutorial button itself with a 'New' chip (hidden by
  default, one-time glow animation) and scroll it into view when
  revealed; tab-level dots now mark getting-started and shortcuts
  instead of documentation
- Translate help.newContentBadge into all 9 locales, reusing the
  established help.documentation.newBadge renderings
- Add HelpManager content-version unit tests (12 cases)

locales/de.json

@@ -2028,7 +2028,8 @@
             "settings": "Einstellungen & Konfiguration",
             "extensions": "Erweiterungen",
             "newBadge": "NEU"
-        }
+        },
+        "newContentBadge": "NEU"
     },
     "update": {
         "title": "Nach Updates suchen",

locales/en.json

@@ -2028,7 +2028,8 @@
       "settings": "Settings & Configuration",
       "extensions": "Extensions",
       "newBadge": "NEW"
-    }
+    },
+    "newContentBadge": "New"
   },
   "update": {
     "title": "Check for Updates",

locales/es.json

@@ -2028,7 +2028,8 @@
             "settings": "Configuración",
             "extensions": "Extensiones",
             "newBadge": "NUEVO"
-        }
+        },
+        "newContentBadge": "NUEVO"
     },
     "update": {
         "title": "Comprobar actualizaciones",

locales/fr.json

@@ -2028,7 +2028,8 @@
             "settings": "Paramètres & Configuration",
             "extensions": "Extensions",
             "newBadge": "NOUVEAU"
-        }
+        },
+        "newContentBadge": "NOUVEAU"
     },
     "update": {
         "title": "Vérifier les mises à jour",

locales/he.json

@@ -2028,7 +2028,8 @@
             "settings": "הגדרות ותצורה",
             "extensions": "הרחבות",
             "newBadge": "חדש"
-        }
+        },
+        "newContentBadge": "חדש"
     },
     "update": {
         "title": "בדוק עדכונים",

locales/ja.json

@@ -2028,7 +2028,8 @@
             "settings": "設定&構成",
             "extensions": "拡張機能",
             "newBadge": "新着"
-        }
+        },
+        "newContentBadge": "新着"
     },
     "update": {
         "title": "更新確認",

locales/ko.json

@@ -2028,7 +2028,8 @@
             "settings": "설정 & 구성",
             "extensions": "확장",
             "newBadge": "신규"
-        }
+        },
+        "newContentBadge": "신규"
     },
     "update": {
         "title": "업데이트 확인",

locales/ru.json

@@ -2028,7 +2028,8 @@
             "settings": "Настройки и конфигурация",
             "extensions": "Расширения",
             "newBadge": "НОВОЕ"
-        }
+        },
+        "newContentBadge": "НОВОЕ"
     },
     "update": {
         "title": "Проверить обновления",

locales/zh-CN.json

@@ -2028,7 +2028,8 @@
             "settings": "设置与配置",
             "extensions": "扩展",
             "newBadge": "新"
-        }
+        },
+        "newContentBadge": "新"
     },
     "update": {
         "title": "检查更新",

locales/zh-TW.json

@@ -2028,7 +2028,8 @@
             "settings": "設定與配置",
             "extensions": "擴充功能",
             "newBadge": "新"
-        }
+        },
+        "newContentBadge": "新"
     },
     "update": {
         "title": "檢查更新",