Add XRayPDF client app with OCR routes

Introduce a new Next.js `client` app for XRayPDF: adds frontend pages (dashboard, upload, layout, Navbar, globals) and API routes for documents (upload, OCR, pixel processing, delete, list). Include Tesseract traineddata (eng.traineddata), update next.config.ts to allow native server packages and remote images, update package.json to add dependencies (canvas, sharp, tesseract.js, pdfjs-dist, multer, uuid), and update Prisma schema. Also add .gitignore entries for user uploads/results and a README describing the project and architecture.

client/src/app/api/documents/[id]/pixel/route.ts

@@ -0,0 +1,124 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getServerSession } from "next-auth";
+import { authOptions } from "@/app/api/auth/[...nextauth]/route";
+import { prisma } from "@/lib/prisma";
+import sharp from "sharp";
+import { readFile, mkdir } from "fs/promises";
+import path from "path";
+
+/**
+ * Pixel-level analysis: renders EVERY page of the PDF as a PNG,
+ * inverts colors and boosts contrast to reveal hidden white-on-white text.
+ * Returns an array of per-page result image paths.
+ */
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await getServerSession(authOptions);
+  if (!session?.user?.email) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const { id } = await params;
+
+  const doc = await prisma.pdfDocument.findUnique({ where: { id } });
+  if (!doc) {
+    return NextResponse.json({ error: "Document not found" }, { status: 404 });
+  }
+
+  const user = await prisma.user.findUnique({
+    where: { email: session.user.email },
+  });
+  if (!user || doc.userId !== user.id) {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  // If already processed, return existing results
+  if (doc.pixelResultDir && doc.pixelPageCount > 0) {
+    const pages = Array.from({ length: doc.pixelPageCount }, (_, i) => ({
+      page: i + 1,
+      path: `${doc.pixelResultDir}/page_${i + 1}.png`,
+    }));
+    return NextResponse.json({ pages, pageCount: doc.pixelPageCount });
+  }
+
+  try {
+    const pdfPath = path.join(process.cwd(), "public", doc.filePath);
+    const pdfBuffer = await readFile(pdfPath);
+
+    const pdfjsLib = await import("pdfjs-dist/legacy/build/pdf.mjs");
+    const loadingTask = pdfjsLib.getDocument({
+      data: new Uint8Array(pdfBuffer),
+    });
+    const pdfDoc = await loadingTask.promise;
+    const numPages = pdfDoc.numPages;
+
+    const resultsDir = path.join(
+      process.cwd(),
+      "public",
+      "results",
+      user.id,
+      id,
+      "pixel"
+    );
+    await mkdir(resultsDir, { recursive: true });
+
+    const publicDir = `/results/${user.id}/${id}/pixel`;
+    const pages: { page: number; path: string }[] = [];
+
+    const { createCanvas } = await import("canvas");
+
+    for (let pageNum = 1; pageNum <= numPages; pageNum++) {
+      const page = await pdfDoc.getPage(pageNum);
+      const scale = 2.0;
+      const viewport = page.getViewport({ scale });
+      const width = Math.floor(viewport.width);
+      const height = Math.floor(viewport.height);
+
+      const canvas = createCanvas(width, height);
+      const ctx = canvas.getContext("2d");
+
+      await page.render({
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        canvasContext: ctx as any,
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        canvas: canvas as any,
+        viewport,
+      }).promise;
+
+      const imageBuffer = canvas.toBuffer("image/png");
+
+      const resultFileName = `page_${pageNum}.png`;
+      const resultPath = path.join(resultsDir, resultFileName);
+
+      await sharp(imageBuffer)
+        .negate({ alpha: false })
+        .normalize()
+        .sharpen()
+        .toFile(resultPath);
+
+      pages.push({
+        page: pageNum,
+        path: `${publicDir}/${resultFileName}`,
+      });
+    }
+
+    await prisma.pdfDocument.update({
+      where: { id },
+      data: {
+        pixelResultDir: publicDir,
+        pixelPageCount: numPages,
+        pageCount: numPages,
+      },
+    });
+
+    return NextResponse.json({ pages, pageCount: numPages });
+  } catch (e) {
+    console.error("Pixel analysis error:", e);
+    return NextResponse.json(
+      { error: "Pixel analysis failed" },
+      { status: 500 }
+    );
+  }
+}