docs(list, menu): clarify request-activation event audience

docs/components/list.md

@@ -433,7 +433,7 @@ Token                                 | Default value
 
 | Event | Type | [Bubbles](https://developer.mozilla.org/en-US/docs/Web/API/Event/bubbles) | [Composed](https://developer.mozilla.org/en-US/docs/Web/API/Event/composed) | Description |
 | --- | --- | --- | --- | --- |
-| `request-activation` | `Event` | Yes | Yes | Requests the list to set `tabindex=0` on the item and focus it. |
+| `request-activation` | `Event` | Yes | Yes | Requests the list to set `tabindex=0` on the item and focus it. Used internally for list keyboard navigation; most applications do not need to listen for this event. It is exposed for authors building their own list-item replacements or wrapping items in a custom controller. |
 
 <!-- mdformat on(autogenerated might break rendering in catalog) -->
 

docs/components/menu.md

@@ -634,7 +634,7 @@ a sharp 0px border radius.](images/menu/theming.webp)
 | Event | Type | [Bubbles](https://developer.mozilla.org/en-US/docs/Web/API/Event/bubbles) | [Composed](https://developer.mozilla.org/en-US/docs/Web/API/Event/composed) | Description |
 | --- | --- | --- | --- | --- |
 | `deactivate-items` | `Event` | Yes | Yes | Requests the parent menu to deselect other items when a submenu opens. |
-| `request-activation` | `Event` | Yes | Yes | Requests the parent to make the slotted item focusable and focus the item. |
+| `request-activation` | `Event` | Yes | Yes | Requests the parent to make the slotted item focusable and focus the item. Used internally for menu keyboard navigation; most applications do not need to listen for this event. It is exposed for authors building their own menu-item replacements, or for advanced cases where you want to call `preventDefault`/`stopPropagation` on it to override default focus handling. |
 | `deactivate-typeahead` | `Event` | Yes | Yes | Requests the parent menu to deactivate the typeahead functionality when a submenu opens. |
 | `activate-typeahead` | `Event` | Yes | Yes | Requests the parent menu to activate the typeahead functionality when a submenu closes. |
 

list/internal/listitem/list-item.ts

@@ -30,7 +30,10 @@ const listItemBaseClass = mixinDelegatesAria(LitElement);
 
 /**
  * @fires request-activation {Event} Requests the list to set `tabindex=0` on
- * the item and focus it. --bubbles --composed
+ * the item and focus it. Used internally for list keyboard navigation; most
+ * applications do not need to listen for this event. It is exposed for
+ * authors building their own list-item replacements or wrapping items in a
+ * custom controller. --bubbles --composed
  */
 export class ListItemEl extends listItemBaseClass implements ListItem {
   /** @nocollapse */

menu/internal/submenu/sub-menu.ts

@@ -30,7 +30,11 @@ import {Corner} from '../menu.js';
  * @fires deactivate-items {Event} Requests the parent menu to deselect other
  * items when a submenu opens. --bubbles --composed
  * @fires request-activation {Event} Requests the parent to make the slotted item
- * focusable and focus the item. --bubbles --composed
+ * focusable and focus the item. Used internally for menu keyboard navigation;
+ * most applications do not need to listen for this event. It is exposed for
+ * authors building their own menu-item replacements, or for advanced cases
+ * where you want to call `preventDefault`/`stopPropagation` on it to override
+ * default focus handling. --bubbles --composed
  * @fires deactivate-typeahead {Event} Requests the parent menu to deactivate
  * the typeahead functionality when a submenu opens. --bubbles --composed
  * @fires activate-typeahead {Event} Requests the parent menu to activate the