fix: remove handle_ prefix from OpenAPI operation IDs and add missing delete endpoint

Co-authored-by: aider (openai/andrew/openrouter/anthropic/claude-sonnet-4) <aider@aider.chat>

src/modes/server/api/mod.rs

@@ -24,6 +24,7 @@ use utoipa_swagger_ui::SwaggerUi;
         status::handle_status,
         item::handle_list_items,
         item::handle_post_item,
+        item::handle_delete_item,
         item::handle_get_item_latest,
         item::handle_get_item_latest_meta,
         item::handle_get_item_latest_content,