Set pdfjs GlobalWorkerOptions.workerSrc at app bootstrap

The PDF.js library refuses to open documents without a worker URL.
Production builds were throwing "No GlobalWorkerOptions.workerSrc
specified" on any upload because neither the source-layer ingest
(extract.ts) nor the viewer adapter ever set one — they relied on the
host application to do it, and the browser bootstrap didn't.

main.tsx now imports the worker via Vite's `?url` suffix so the file
is bundled into the build, and sets GlobalWorkerOptions.workerSrc
once before any PDF code runs. Added src/vite-env.d.ts so TypeScript
knows about the `?url` import suffix.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/app/main.tsx

@@ -1,7 +1,16 @@
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
+import * as pdfjs from "pdfjs-dist";
+// Vite resolves `?url` to a bundled asset URL the browser can fetch.
+import pdfWorkerUrl from "pdfjs-dist/build/pdf.worker.min.mjs?url";
+
 import { App } from "./App";
 
+// PDF.js needs a worker URL before any PDF is parsed. Set it once at app
+// bootstrap so both the source-layer ingest (extract.ts) and the viewer
+// adapter (PdfSpikeViewer) can open documents.
+pdfjs.GlobalWorkerOptions.workerSrc = pdfWorkerUrl;
+
 const container = document.getElementById("root");
 if (!container) throw new Error("#root not found");
 

src/vite-env.d.ts

@@ -0,0 +1 @@
+/// <reference types="vite/client" />