Add extract_document tool and improve artifacts tab scrolling

- Add extract_document tool for extracting text from PDF/DOCX/XLSX/PPTX from URLs
- CORS proxy support from settings for fetching documents
- Proper error messages guiding users on CORS issues and manual file attachment
- Add scroll-into-view for active artifact tabs
- Export extract_document tool from web-ui package

packages/web-ui/src/tools/index.ts

@@ -1,5 +1,6 @@
 import type { ToolResultMessage } from "@mariozechner/pi-ai";
 import "./javascript-repl.js"; // Auto-registers the renderer
+import "./extract-document.js"; // Auto-registers the renderer
 import { getToolRenderer, registerToolRenderer } from "./renderer-registry.js";
 import { BashRenderer } from "./renderers/BashRenderer.js";
 import { DefaultRenderer } from "./renderers/DefaultRenderer.js";