feat(portfolio): add export functionality with privacy warning

client/src/components/portfolio/PortfolioDashboard.tsx

@@ -12,6 +12,7 @@ import PortfolioVisualizer from "../visualizer/PortfolioVisualizer";
 import { ExposureMap } from "../../portfolio/ExposureMap";
 import PresetsPanel from "../../features/presets/PresetsPanel";
 import UnifiedActivityTimeline from "./UnifiedActivityTimeline";
+import PortfolioExport from "./PortfolioExport";
 
 // ── Types ───────────────────────────────────────────────────────────────
 
@@ -126,12 +127,15 @@ export default function PortfolioDashboard({ walletAddress }: PortfolioDashboard
             {walletAddress.slice(0, 8)}...{walletAddress.slice(-8)}
           </p>
         </div>
-        <button
-          onClick={() => { setIsLoading(true); setTimeout(() => setIsLoading(false), 500); }}
-          className="btn-secondary flex items-center gap-2 text-sm"
-        >
-          <RefreshCw size={14} /> Refresh
-        </button>
+        <div className="flex items-center gap-3">
+          <PortfolioExport walletAddress={walletAddress} />
+          <button
+            onClick={() => { setIsLoading(true); setTimeout(() => setIsLoading(false), 500); }}
+            className="btn-secondary flex items-center gap-2 text-sm"
+          >
+            <RefreshCw size={14} /> Refresh
+          </button>
+        </div>
       </div>
 
       {/* Stats Cards */}

client/src/components/portfolio/PortfolioExport.test.tsx

@@ -0,0 +1,79 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { render, screen, fireEvent, waitFor } from "@testing-library/react";
+import "@testing-library/jest-dom";
+import PortfolioExport from "./PortfolioExport";
+
+const STORAGE_KEY = "stellar_yield_portfolio_export_privacy_warning_dismissed";
+
+describe("PortfolioExport", () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  afterEach(() => {
+    vi.resetAllMocks();
+  });
+
+  it("shows a privacy warning before export and persists dismissal when requested", async () => {
+    const urlMock = vi.fn().mockReturnValue("blob:url");
+    Object.defineProperty(window, "URL", {
+      configurable: true,
+      value: {
+        ...window.URL,
+        createObjectURL: urlMock,
+        revokeObjectURL: vi.fn(),
+      },
+    });
+
+    const clickSpy = vi.spyOn(HTMLAnchorElement.prototype, "click").mockImplementation(() => undefined);
+
+    (globalThis.fetch as unknown) = vi.fn().mockResolvedValueOnce(
+      new Response(new Blob(["col1,col2\nvalue1,value2"], { type: "text/csv" }), {
+        status: 200,
+        headers: { "Content-Disposition": 'attachment; filename="portfolio-export.csv"' },
+      }),
+    );
+
+    render(<PortfolioExport walletAddress="GDETESTWALLET123" />);
+
+    fireEvent.click(screen.getByRole("button", { name: /export portfolio/i }));
+
+    expect(screen.getByRole("dialog")).toBeInTheDocument();
+    fireEvent.click(screen.getByLabelText(/don't show this warning again/i));
+    fireEvent.click(screen.getByRole("button", { name: /confirm export/i }));
+
+    await waitFor(() => expect(globalThis.fetch).toHaveBeenCalledTimes(1));
+    expect(urlMock).toHaveBeenCalled();
+    expect(clickSpy).toHaveBeenCalled();
+    expect(localStorage.getItem(STORAGE_KEY)).toBe("true");
+  });
+
+  it("skips the warning dialog when the warning has already been dismissed", async () => {
+    localStorage.setItem(STORAGE_KEY, "true");
+
+    Object.defineProperty(window, "URL", {
+      configurable: true,
+      value: {
+        ...window.URL,
+        createObjectURL: vi.fn().mockReturnValue("blob:url"),
+        revokeObjectURL: vi.fn(),
+      },
+    });
+    vi.spyOn(HTMLAnchorElement.prototype, "click").mockImplementation(() => undefined);
+
+    (globalThis.fetch as unknown) = vi.fn().mockResolvedValueOnce(
+      new Response(new Blob(["col1,col2\nvalue1,value2"], { type: "text/csv" }), {
+        status: 200,
+        headers: { "Content-Disposition": 'attachment; filename="portfolio-export.csv"' },
+      }),
+    );
+
+    render(<PortfolioExport walletAddress="GDETESTWALLET123" />);
+
+    fireEvent.click(screen.getByRole("button", { name: /export portfolio/i }));
+
+    await waitFor(() => expect(globalThis.fetch).toHaveBeenCalledTimes(1));
+    expect(screen.queryByRole("dialog")).not.toBeInTheDocument();
+  });
+});

client/src/components/portfolio/PortfolioExport.tsx

@@ -0,0 +1,175 @@
+import { useEffect, useState } from "react";
+import { Download, AlertTriangle } from "lucide-react";
+
+const STORAGE_KEY = "stellar_yield_portfolio_export_privacy_warning_dismissed";
+
+function readWarningDismissed(): boolean {
+  try {
+    return window.localStorage.getItem(STORAGE_KEY) === "true";
+  } catch {
+    return false;
+  }
+}
+
+function saveWarningDismissed(): void {
+  try {
+    window.localStorage.setItem(STORAGE_KEY, "true");
+  } catch {
+    // Ignore storage failures intentionally.
+  }
+}
+
+interface PortfolioExportProps {
+  walletAddress: string;
+}
+
+export default function PortfolioExport({ walletAddress }: PortfolioExportProps) {
+  const [showWarningModal, setShowWarningModal] = useState(false);
+  const [warningDismissed, setWarningDismissed] = useState(false);
+  const [rememberWarning, setRememberWarning] = useState(false);
+  const [isExporting, setIsExporting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    setWarningDismissed(readWarningDismissed());
+  }, []);
+
+  const downloadFile = async () => {
+    setError(null);
+    setIsExporting(true);
+
+    try {
+      const response = await fetch(
+        `/api/users/${encodeURIComponent(walletAddress)}/export`,
+      );
+
+      if (!response.ok) {
+        let message = "Failed to generate export.";
+        try {
+          const body = await response.json();
+          if (body?.message) message = body.message;
+        } catch {
+          // ignore JSON parse errors
+        }
+        throw new Error(message);
+      }
+
+      const blob = await response.blob();
+      const url = window.URL.createObjectURL(blob);
+      const filename =
+        response.headers
+          .get("Content-Disposition")
+          ?.match(/filename="(.+)"/)?.[1] ?? "portfolio-export.csv";
+
+      const anchor = document.createElement("a");
+      anchor.href = url;
+      anchor.download = filename;
+      document.body.appendChild(anchor);
+      anchor.click();
+      window.URL.revokeObjectURL(url);
+      document.body.removeChild(anchor);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Failed to generate export.");
+    } finally {
+      setIsExporting(false);
+    }
+  };
+
+  const handleExportClick = () => {
+    if (warningDismissed) {
+      void downloadFile();
+      return;
+    }
+
+    setShowWarningModal(true);
+  };
+
+  const handleConfirmExport = async () => {
+    if (rememberWarning) {
+      saveWarningDismissed();
+      setWarningDismissed(true);
+    }
+    setShowWarningModal(false);
+    await downloadFile();
+  };
+
+  return (
+    <div className="flex flex-col items-end gap-2">
+      <button
+        type="button"
+        onClick={handleExportClick}
+        disabled={isExporting}
+        className="btn-secondary flex items-center gap-2 text-sm"
+      >
+        <Download size={14} />
+        Export Portfolio
+      </button>
+
+      {error ? (
+        <p className="text-right text-sm text-red-400">{error}</p>
+      ) : null}
+
+      {showWarningModal ? (
+        <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-slate-950/70">
+          <div
+            role="dialog"
+            aria-modal="true"
+            aria-labelledby="portfolio-export-warning-title"
+            className="w-full max-w-lg rounded-[32px] border border-slate-800 bg-slate-950 p-6 text-white shadow-2xl"
+          >
+            <div className="flex items-start gap-3">
+              <div className="rounded-2xl bg-orange-500/10 p-3 text-orange-300">
+                <AlertTriangle size={20} />
+              </div>
+              <div className="space-y-3">
+                <div>
+                  <h2 className="text-xl font-semibold">Portfolio export privacy warning</h2>
+                  <p className="text-sm text-slate-400 mt-1">
+                    Your export may include wallet address, portfolio balances, asset details, and transaction history.
+                  </p>
+                </div>
+
+                <div className="rounded-3xl border border-slate-800 bg-slate-900 p-4 text-sm text-slate-300">
+                  <p className="font-semibold text-slate-100">What will be included</p>
+                  <ul className="mt-2 space-y-2 list-disc pl-5">
+                    <li>Wallet address and account identifier</li>
+                    <li>Asset holdings and current balances</li>
+                    <li>Recent portfolio transaction history</li>
+                  </ul>
+                </div>
+
+                <label className="inline-flex items-center gap-2 text-sm text-slate-300">
+                  <input
+                    type="checkbox"
+                    checked={rememberWarning}
+                    onChange={(event) => setRememberWarning(event.target.checked)}
+                    className="h-4 w-4 rounded border-slate-600 bg-slate-800 text-slate-100"
+                  />
+                  Don't show this warning again
+                </label>
+
+                <div className="flex flex-col gap-3 sm:flex-row sm:justify-end">
+                  <button
+                    type="button"
+                    onClick={() => setShowWarningModal(false)}
+                    className="w-full rounded-2xl border border-slate-700 bg-slate-800 px-4 py-3 text-sm text-slate-200 transition hover:border-slate-500 sm:w-auto"
+                  >
+                    Cancel
+                  </button>
+                  <button
+                    type="button"
+                    onClick={handleConfirmExport}
+                    disabled={isExporting}
+                    className="w-full rounded-2xl bg-slate-100 px-4 py-3 text-sm font-semibold text-slate-950 transition hover:bg-slate-200 disabled:opacity-60 sm:w-auto"
+                  >
+                    Confirm export
+                  </button>
+                </div>
+              </div>
+            </div>
+          </div>
+        </div>
+      ) : null}
+    </div>
+  );
+}