feat: add authenticated screenshot utility for Paperclip UI

Reads board token from ~/.paperclip/auth.json and injects it as a
Bearer header via Playwright, enabling agents to take screenshots
of authenticated pages without storing email/password credentials.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

scripts/screenshot.cjs

@@ -0,0 +1,86 @@
+#!/usr/bin/env node
+/**
+ * Screenshot utility for Paperclip UI.
+ *
+ * Reads the board token from ~/.paperclip/auth.json and injects it as a
+ * Bearer header so Playwright can access authenticated pages.
+ *
+ * Usage:
+ *   node scripts/screenshot.cjs <url-or-path> [output.png] [--width 1280] [--height 800] [--wait 2000]
+ *
+ * Examples:
+ *   node scripts/screenshot.cjs /PAPA/agents/cto/instructions /tmp/shot.png
+ *   node scripts/screenshot.cjs http://localhost:5173/PAPA/agents/cto/instructions
+ */
+
+const fs = require("fs");
+const path = require("path");
+const os = require("os");
+
+// --- CLI args -----------------------------------------------------------
+const args = process.argv.slice(2);
+function flag(name, fallback) {
+  const i = args.indexOf(`--${name}`);
+  if (i === -1) return fallback;
+  const val = args.splice(i, 2)[1];
+  return Number(val) || fallback;
+}
+const width = flag("width", 1280);
+const height = flag("height", 800);
+const waitMs = flag("wait", 2000);
+
+const rawUrl = args[0];
+const outPath = args[1] || "/tmp/paperclip-screenshot.png";
+
+if (!rawUrl) {
+  console.error("Usage: node scripts/screenshot.cjs <url-or-path> [output.png]");
+  process.exit(1);
+}
+
+// --- Auth ----------------------------------------------------------------
+function loadBoardToken() {
+  const authPath = path.resolve(os.homedir(), ".paperclip/auth.json");
+  try {
+    const auth = JSON.parse(fs.readFileSync(authPath, "utf-8"));
+    const creds = auth.credentials || {};
+    const entry = Object.values(creds)[0];
+    if (entry && entry.token) return { token: entry.token, apiBase: entry.apiBase };
+  } catch (_) {
+    // ignore
+  }
+  return null;
+}
+
+const cred = loadBoardToken();
+if (!cred) {
+  console.error("No board token found in ~/.paperclip/auth.json");
+  process.exit(1);
+}
+
+// Resolve URL — if it starts with / treat as path relative to apiBase
+const url = rawUrl.startsWith("http") ? rawUrl : `${cred.apiBase}${rawUrl}`;
+
+// --- Screenshot ----------------------------------------------------------
+(async () => {
+  const { chromium } = require("playwright");
+  const browser = await chromium.launch();
+  const context = await browser.newContext({
+    viewport: { width, height },
+    extraHTTPHeaders: {
+      Authorization: `Bearer ${cred.token}`,
+    },
+  });
+
+  const page = await context.newPage();
+  try {
+    await page.goto(url, { waitUntil: "networkidle", timeout: 20000 });
+    await page.waitForTimeout(waitMs);
+    await page.screenshot({ path: outPath, fullPage: false });
+    console.log(`Saved: ${outPath}`);
+  } catch (err) {
+    console.error(`Screenshot failed: ${err.message}`);
+    process.exit(1);
+  } finally {
+    await browser.close();
+  }
+})();