refactor: remove unused DELETE /chats/{id}/tags/all endpoint (#24785)

The bulk-clear-chat-tags endpoint's only frontend wrapper,
deleteTagsById in src/lib/apis/chats/index.ts, is dead: nothing imports
or calls it, the path is referenced nowhere else, and the route handler
has no internal caller. Removes the route handler, the dead wrapper, and
the now-orphaned Chats.delete_all_tags_by_id_and_user_id model method
(its sole caller was this route). The shared
Chats.delete_orphan_tags_for_user method is untouched.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/apis/chats/index.ts

@@ -1206,37 +1206,6 @@ export const deleteTagById = async (token: string, id: string, tagName: string)
 
 	return res;
 };
-export const deleteTagsById = async (token: string, id: string) => {
-	let error = null;
-
-	const res = await fetch(`${WEBUI_API_BASE_URL}/chats/${id}/tags/all`, {
-		method: 'DELETE',
-		headers: {
-			Accept: 'application/json',
-			'Content-Type': 'application/json',
-			...(token && { authorization: `Bearer ${token}` })
-		}
-	})
-		.then(async (res) => {
-			if (!res.ok) throw await res.json();
-			return res.json();
-		})
-		.then((json) => {
-			return json;
-		})
-		.catch((err) => {
-			error = err;
-
-			console.error(err);
-			return null;
-		});
-
-	if (error) {
-		throw error;
-	}
-
-	return res;
-};
 
 export const deleteAllChats = async (token: string) => {
 	let error = null;