Add TinyMCE AI feature banner to premium plugins index

Author: kemister85

modules/ROOT/partials/index-pages/premium-plugins.adoc

@@ -1,5 +1,7 @@
 This section lists the premium plugins provided by {productname}.
 
+include::partial$misc/admon-plugins-tinymce-ai-feature.adoc[]
+
 [cols="1,1"]
 |===
 
@@ -17,9 +19,9 @@ Replace common typewriter-style characters with their professional typesetter eq
 
 a|
 [.lead]
-xref:ai.adoc[AI Assistant]
+xref:ai.adoc[AI Assistant (legacy)]
 
-Send queries to registered AI APIs and set the results in the current document.
+Earlier plugin for sending queries to registered AI APIs and inserting results into the document. New integrations are documented under xref:tinymceai-introduction.adoc[TinyMCE AI].
 
 a|
 [.lead]
@@ -200,12 +202,6 @@ xref:tableofcontents.adoc[Table of Contents]
 
 Insert a simple Table of Contents into the {productname} editor.
 
-a|
-[.lead]
-xref:tinymceai-introduction.adoc[TinyMCE AI]
-
-AI-powered features for {productname} including AI chat, AI review, and quick actions.
-
 a|
 [.lead]
 xref:tinydrive-introduction.adoc[Tiny Drive]

modules/ROOT/partials/misc/admon-plugins-tinymce-ai-feature.adoc

@@ -0,0 +1,44 @@
+// Plugins index — TinyMCE AI feature advert. Self-contained styles (not shared with admon-promo-banner).
+++++
+<style>
+.plugins-ai-feature-banner {
+  --radius: 3px;
+  position: relative;
+  padding: 1rem;
+  background: #f9f9fb;
+  margin: 1rem 0;
+  border: 1px solid #e2e5ed;
+  border-radius: var(--radius) 0 0 var(--radius);
+}
+
+/* Same left bar as default .signup-promo::before in admon-promo-banner.adoc (coral → blue, not tinymce-ai green) */
+.plugins-ai-feature-banner::before {
+  content: '';
+  position: absolute;
+  top: -1px; bottom: -1px; left: -1px;
+  width: 5px;
+  background: linear-gradient(to bottom, #F66 15%, #4D66CB 85%);
+  border-radius: var(--radius) 0 0 var(--radius)
+}
+
+.plugins-ai-feature-banner .paragraph:first-child {
+  margin-top: 0;
+}
+
+.plugins-ai-feature-banner .paragraph:last-child {
+  margin-bottom: 0;
+}
+
+.plugins-ai-feature-banner .paragraph + .paragraph {
+  margin-top: 0.5em;
+}
+</style>
+++++
+
+[.plugins-ai-feature-banner]
+--
+[.lead]
+xref:tinymceai-introduction.adoc[TinyMCE AI]
+
+AI-powered features for {productname} including AI chat, AI review, and quick actions.
+--