feat: add permission toggle for public sharing of notes

This commit introduces a new permission toggle that allows administrators to control whether users can publicly share their notes.

- Adds a new environment variable `USER_PERMISSIONS_NOTES_ALLOW_PUBLIC_SHARING` to control the default setting.
- Adds a `public_notes` permission to the `sharing` section of the user permissions.
- Adds a toggle switch to the admin panel for managing this permission.
- Implements backend logic to enforce the permission when a user attempts to share a note publicly.

src/lib/components/admin/Users/Groups/Permissions.svelte

@@ -17,7 +17,8 @@
 			public_models: false,
 			public_knowledge: false,
 			public_prompts: false,
-			public_tools: false
+			public_tools: false,
+			public_notes: false
 		},
 		chat: {
 			controls: true,
@@ -247,6 +248,13 @@
 			</div>
 			<Switch bind:state={permissions.sharing.public_tools} />
 		</div>
+
+		<div class="  flex w-full justify-between my-2 pr-2">
+			<div class=" self-center text-xs font-medium">
+				{$i18n.t('Notes Public Sharing')}
+			</div>
+			<Switch bind:state={permissions.sharing.public_notes} />
+		</div>
 	</div>
 
 	<hr class=" border-gray-100 dark:border-gray-850 my-2" />