fix: add beta warning and remove 'new in v3' language

Author: ManukMinasyan

docs/content/1.getting-started/1.installation.md

@@ -5,6 +5,10 @@ navigation:
   icon: i-lucide-download
 ---
 
+::alert{type="warning"}
+**Beta Release**: Custom Fields v3 is currently in beta. While stable for production use, some APIs may change before the final release.
+::
+
 Get started with Custom Fields in just a few steps.
 
 ## Requirements

docs/content/3.upgrading/1.upgrade-guide.md

@@ -6,7 +6,7 @@ navigation:
 ---
 
 ::alert{type="info"}
-Custom Fields v3 builds on the fluent builder API introduced in v2 while providing enhanced performance and new capabilities.
+Custom Fields v3 builds on the fluent builder API introduced in v2.
 ::
 
 ## Quick Upgrade
@@ -263,9 +263,7 @@ php artisan view:clear
 php artisan filament:cache-components
 ```
 
-## New Features in v3
-
-### Fluent Builder API
+## Fluent Builder API
 
 The builder API provides more control and flexibility: