diff --git a/periscope/src/frontend/scripts/sync-version.mjs b/periscope/src/frontend/scripts/sync-version.mjs
new file mode 100644
index 0000000..add5e57
--- /dev/null
+++ b/periscope/src/frontend/scripts/sync-version.mjs
@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+/** Stamp APP_VERSION from the latest changelog heading into version.ts and package.json. */
+
+import { readFileSync, writeFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const root = join(dirname(fileURLToPath(import.meta.url)), "..");
+const changelog = join(root, "content", "changelog.md");
+const versionFile = join(root, "src", "lib", "version.ts");
+const pkgFile = join(root, "package.json");
+
+const text = readFileSync(changelog, "utf-8");
+const hit = text.match(
+  /^##\s+(\d+\.\d+\.\d+)(?:\s+[—-]\s+(\d{4}-\d{2}-\d{2}))?/m,
+);
+if (!hit) {
+  console.error(`[sync-version] no ## X.Y.Z heading in ${changelog}`);
+  process.exit(1);
+}
+
+const version = hit[1];
+const date = hit[2] ?? "";
+const generated = `/** Stamped from content/changelog.md by scripts/sync-version.mjs. */
+export const APP_VERSION = "${version}";
+export const APP_VERSION_DATE = "${date}";
+`;
+
+let tsDirty = true;
+try {
+  tsDirty = readFileSync(versionFile, "utf-8") !== generated;
+} catch {
+  tsDirty = true;
+}
+if (tsDirty) writeFileSync(versionFile, generated);
+
+const pkg = JSON.parse(readFileSync(pkgFile, "utf-8"));
+const pkgDirty = pkg.version !== version;
+if (pkgDirty) {
+  pkg.version = version;
+  writeFileSync(pkgFile, JSON.stringify(pkg, null, 2) + "\n");
+}
+
+if (tsDirty || pkgDirty) {
+  const bits = [
+    tsDirty ? "version.ts" : "",
+    pkgDirty ? "package.json" : "",
+  ].filter(Boolean);
+  console.log(`[sync-version] Synced to ${version} (${bits.join(" + ")}).`);
+} else {
+  console.log(`[sync-version] Already at ${version}.`);
+}
diff --git a/periscope/src/frontend/src/lib/report-export.ts b/periscope/src/frontend/src/lib/report-export.ts
new file mode 100644
index 0000000..60e30e0
--- /dev/null
+++ b/periscope/src/frontend/src/lib/report-export.ts
@@ -0,0 +1,60 @@
+/** Client-side findings workbook (.xlsx) for a finished review. */
+
+import * as XLSX from "xlsx";
+import type { DesignGraph, Finding, ValidationReport } from "./types";
+import { sortFindings } from "./utils";
+
+const COLUMNS = [
+  "Designator",
+  "MPN",
+  "ID",
+  "Severity",
+  "Title",
+  "Description",
+  "Recommendation",
+  "Source",
+  "Net",
+  "Pins",
+  "Rule",
+] as const;
+
+const WIDTHS = [12, 20, 12, 10, 44, 60, 50, 24, 16, 16, 14];
+
+function sourceCell(f: Finding): string {
+  if (f.source && f.source !== "review") return "Automated check";
+  const who = f.source_designator || f.designator;
+  return f.source_page ? `${who} datasheet p.${f.source_page}` : `${who} datasheet`;
+}
+
+function fileStem(name: string): string {
+  const slug = name.replace(/[^a-zA-Z0-9]+/g, "-").replace(/^-+|-+$/g, "");
+  return slug || "report";
+}
+
+export function exportReportToExcel(
+  report: ValidationReport,
+  graph: DesignGraph,
+  projectName?: string,
+): void {
+  const body = sortFindings(report.findings).map((f) => [
+    f.designator,
+    f.mpn || graph.components[f.designator]?.mpn || "",
+    f.finding_id ?? "",
+    f.status,
+    f.finding,
+    f.why ?? "",
+    f.recommendation ?? "",
+    sourceCell(f),
+    f.net ?? "",
+    (f.pins ?? []).join(", "),
+    f.rule_id ?? "",
+  ]);
+  const sheet = XLSX.utils.aoa_to_sheet([COLUMNS, ...body]);
+  sheet["!cols"] = WIDTHS.map((wch) => ({ wch }));
+  const book = XLSX.utils.book_new();
+  XLSX.utils.book_append_sheet(book, sheet, "Findings");
+  XLSX.writeFile(
+    book,
+    `${fileStem(projectName || report.project || "report")}-findings.xlsx`,
+  );
+}
diff --git a/periscope/src/frontend/src/lib/site.ts b/periscope/src/frontend/src/lib/site.ts
new file mode 100644
index 0000000..2b8c512
--- /dev/null
+++ b/periscope/src/frontend/src/lib/site.ts
@@ -0,0 +1,67 @@
+/** Public identity of this Periscope instance (not Faradworks). */
+
+import type { Metadata } from "next";
+
+export const SITE_URL = (
+  process.env.NEXT_PUBLIC_SITE_URL?.trim().replace(/\/$/, "") ||
+  "https://periscope.michelebigi.it"
+);
+
+export const SITE_NAME = "Periscope";
+
+export const SITE_DESCRIPTION =
+  "Periscope reviews your schematic against every datasheet and catches the errors that would otherwise surface at bring-up. Works with KiCad, Altium, OrCAD, Cadence, Siemens, EasyEDA, and EAGLE.";
+
+export const SITE_TAGLINE = "Agentic schematic validation";
+
+export const OPERATOR_NAME = "Michele Bigi";
+
+export const CONTACT_EMAIL = "mikbigi@gmail.com";
+
+/** Unset: this operator has no X/Twitter handle. */
+export const TWITTER_HANDLE: string | undefined = undefined;
+
+export function pageMetadata({
+  title,
+  description,
+  path,
+}: {
+  title: string;
+  description: string;
+  path: string;
+}): Metadata {
+  const url = path.startsWith("/") ? path : `/${path}`;
+  const fullTitle = `${title} · ${SITE_NAME}`;
+  const twitter: NonNullable<Metadata["twitter"]> = {
+    card: "summary_large_image",
+    title: fullTitle,
+    description,
+    images: ["/twitter-image"],
+  };
+  if (TWITTER_HANDLE) {
+    twitter.site = TWITTER_HANDLE;
+    twitter.creator = TWITTER_HANDLE;
+  }
+  return {
+    title,
+    description,
+    alternates: { canonical: url },
+    openGraph: {
+      type: "website",
+      siteName: SITE_NAME,
+      locale: "en_US",
+      url,
+      title: fullTitle,
+      description,
+      images: [
+        {
+          url: "/opengraph-image",
+          width: 1200,
+          height: 630,
+          alt: `${SITE_NAME} — ${SITE_TAGLINE}`,
+        },
+      ],
+    },
+    twitter,
+  };
+}
diff --git a/periscope/src/frontend/src/lib/version.ts b/periscope/src/frontend/src/lib/version.ts
new file mode 100644
index 0000000..d3cfc78
--- /dev/null
+++ b/periscope/src/frontend/src/lib/version.ts
@@ -0,0 +1,3 @@
+/** Stamped from content/changelog.md by scripts/sync-version.mjs. */
+export const APP_VERSION = "2.52.0";
+export const APP_VERSION_DATE = "2026-09-20";
diff --git a/tests/test_periscope_frontend_site_rewrite.py b/tests/test_periscope_frontend_site_rewrite.py
new file mode 100644
index 0000000..f19fbd0
--- /dev/null
+++ b/tests/test_periscope_frontend_site_rewrite.py
@@ -0,0 +1,47 @@
+"""Native frontend site/version/export modules live under periscope/src."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+SRC = ROOT / "periscope" / "src" / "frontend"
+
+
+def test_site_version_export_are_src():
+    for rel in (
+        "src/lib/site.ts",
+        "src/lib/version.ts",
+        "src/lib/report-export.ts",
+        "scripts/sync-version.mjs",
+    ):
+        path = SRC / rel
+        assert path.is_file(), rel
+        assert "Native Periscope overlay" not in path.read_text(encoding="utf-8")[:400]
+
+
+def test_site_exports():
+    text = (SRC / "src/lib/site.ts").read_text(encoding="utf-8")
+    for name in (
+        "SITE_URL",
+        "SITE_NAME",
+        "SITE_DESCRIPTION",
+        "SITE_TAGLINE",
+        "OPERATOR_NAME",
+        "CONTACT_EMAIL",
+        "TWITTER_HANDLE",
+        "pageMetadata",
+    ):
+        assert name in text
+
+
+def test_report_export_entry():
+    text = (SRC / "src/lib/report-export.ts").read_text(encoding="utf-8")
+    assert "export function exportReportToExcel" in text
+    assert "Findings" in text
+
+
+def test_version_constants():
+    text = (SRC / "src/lib/version.ts").read_text(encoding="utf-8")
+    assert "export const APP_VERSION" in text
+    assert "export const APP_VERSION_DATE" in text