feat(header): add new NFS header (#2783)

Signed-off-by: Rohit Rai <rohitkrai03@gmail.com>

Author: rohitkrai03

workspaces/global-header/.changeset/famous-bottles-marry.md

@@ -0,0 +1,5 @@
+---
+'@red-hat-developer-hub/backstage-plugin-global-header': minor
+---
+
+Added a new frontend system based header

workspaces/global-header/app-config.yaml

@@ -1,6 +1,18 @@
 app:
   title: RHDH Global Header Test App
   baseUrl: http://localhost:3000
+
+  packages: all
+
+  extensions:
+    - api:app/app-language:
+        config:
+          availableLanguages: ['en', 'de', 'fr', 'it', 'es', 'ja']
+          defaultLanguage: 'en'
+    - page:catalog:
+        config:
+          path: /
+
   support:
     url: https://access.redhat.com/products/red-hat-developer-hub
     items:
@@ -11,6 +23,39 @@ app:
           - url: https://access.redhat.com/documentation/en-us/red_hat_developer_hub
             title: Documentation
 
+globalHeader:
+  components:
+    - title: Visualizer Dashboard
+      icon: dashboard
+      link: /visualizer/tree
+      priority: 75
+
+  menuItems:
+    - target: app-launcher
+      title: Internal Wiki
+      icon: article
+      link: https://wiki.internal.example.com
+      sectionLabel: Resources
+      priority: 80
+    - target: app-launcher
+      title: Issue Tracker
+      icon: bug_report
+      link: https://issues.internal.example.com
+      sectionLabel: Resources
+      priority: 70
+    - target: help
+      title: FAQ
+      icon: quiz
+      link: https://faq.example.com
+      sectionLabel: Support
+      priority: 90
+    - target: help
+      title: Community Forum
+      icon: forum
+      link: https://forum.example.com
+      sectionLabel: Support
+      priority: 80
+
 organization:
   name: My Company
 

workspaces/global-header/docs/index.md

@@ -1,9 +1,16 @@
-# Global header
+# Global Header
 
-Red Hat Developer Hub includes a new configable and highly extendable global header plugin starting with RHDH 1.5.
+Red Hat Developer Hub includes a configurable and highly extensible global header plugin starting with RHDH 1.5.
 
 By default it includes a Search input field, Create, Starred[^1], Support[^2] and Notifications[^3] icon buttons and a user profile dropdown.
 
-[^1]: Only when an enitity is starred.
+The plugin supports two integration modes:
+
+- **New Frontend System** -- Extension blueprints (`GlobalHeaderComponentBlueprint`, `GlobalHeaderMenuItemBlueprint`) allow any plugin to contribute toolbar items and dropdown menu items. See the [New Frontend System Guide](new-frontend-system.md) for full details, including architecture, code examples, and API reference.
+- **Legacy Mount Points** -- Dynamic plugin mount points for traditional Backstage apps. See [Configuration](configuration.md).
+
+Deployers can also add menu items directly via `app-config.yaml` without writing any plugin code. See [Config-Driven Menu Items](new-frontend-system.md#config-driven-menu-items).
+
+[^1]: Only when an entity is starred.
 [^2]: Only when the Support URL is configured in the `app-config.yaml`.
 [^3]: Only when the notifications plugin is installed.