feat(miner-ui): add an optional ORB/Grafana footer link to the root layout

apps/gittensory-miner-ui/README.md

@@ -9,3 +9,9 @@ The miner package invariant is client-side only with no required phone-home to b
 local miner CLI can serve later — not a Wrangler deploy target.
 
 Phase 6 data views (run history, portfolio cards) land in follow-up issues after this empty shell.
+
+## Configuration
+
+| Env var                     | Required | Description                                                                                                                                                                                                                                            |
+| --------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `VITE_MINER_UI_GRAFANA_URL` | No       | If set (and non-empty), renders a footer link to your ORB/Grafana dashboard at this URL. Unset ⇒ no link. Must be `VITE_`-prefixed so Vite exposes it to the client bundle. It is a plain navigational link — no token or credential is ever appended. |

apps/gittensory-miner-ui/src/components/grafana-footer-link.tsx

@@ -0,0 +1,23 @@
+// Optional footer link to an operator's ORB/Grafana dashboard (#5194). Rendered only when the operator sets
+// VITE_MINER_UI_GRAFANA_URL (Vite exposes only VITE_-prefixed vars to the client bundle; a bare name would be
+// undefined at build time). The URL is a plain navigational link — no auth/session token or credential is ever
+// appended, and it is rendered as a normal href attribute (React escapes it, so a misconfigured value cannot
+// inject markup). Renders nothing when the var is unset or empty.
+export function GrafanaFooterLink() {
+  const url = import.meta.env.VITE_MINER_UI_GRAFANA_URL;
+  // Own the whole <footer> wrapper and return null for ALL of it when unset — otherwise a wrapper rendered by
+  // the layout would leave an empty, padded footer visible even though there is no link to show.
+  if (!url) return null;
+  return (
+    <footer className="mx-auto max-w-5xl px-6 py-4 text-token-sm text-muted-foreground">
+      <a
+        href={url}
+        target="_blank"
+        rel="noopener noreferrer"
+        className="hover-surface rounded-token-sm px-2 py-1 hover:text-foreground"
+      >
+        ORB / Grafana dashboard ↗
+      </a>
+    </footer>
+  );
+}

apps/gittensory-miner-ui/src/grafana-footer-link.test.tsx

@@ -0,0 +1,34 @@
+import { render, screen } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { GrafanaFooterLink } from "./components/grafana-footer-link";
+
+afterEach(() => vi.unstubAllEnvs());
+
+describe("GrafanaFooterLink (#5194)", () => {
+  it("renders a footer with a new-tab link to the configured dashboard URL", () => {
+    vi.stubEnv("VITE_MINER_UI_GRAFANA_URL", "https://grafana.example.internal/d/ams");
+    render(<GrafanaFooterLink />);
+    expect(screen.getByRole("contentinfo")).toBeTruthy(); // the <footer> itself
+    const link = screen.getByRole("link", { name: /Grafana dashboard/i });
+    expect(link.getAttribute("href")).toBe("https://grafana.example.internal/d/ams");
+    expect(link.getAttribute("target")).toBe("_blank");
+    expect(link.getAttribute("rel")).toBe("noopener noreferrer");
+  });
+
+  it("renders NOTHING when unset/empty — no footer wrapper, not just no link", () => {
+    vi.stubEnv("VITE_MINER_UI_GRAFANA_URL", "");
+    const { container } = render(<GrafanaFooterLink />);
+    expect(container.firstChild).toBeNull();
+    expect(screen.queryByRole("contentinfo")).toBeNull(); // no empty padded <footer> either
+    expect(screen.queryByRole("link")).toBeNull();
+  });
+
+  it("uses the URL verbatim as the href — never appends a token or credential", () => {
+    const url = "https://dash.example.internal/grafana";
+    vi.stubEnv("VITE_MINER_UI_GRAFANA_URL", url);
+    render(<GrafanaFooterLink />);
+    const href = screen.getByRole("link").getAttribute("href") ?? "";
+    expect(href).toBe(url); // exact — no `?token=`, no appended session/credential
+    expect(href).not.toMatch(/token|api[_-]?key|secret|session|auth=/i);
+  });
+});

apps/gittensory-miner-ui/src/routes/__root.tsx

@@ -1,4 +1,5 @@
 import { Outlet, createRootRoute, Link } from "@tanstack/react-router";
+import { GrafanaFooterLink } from "@/components/grafana-footer-link";
 
 export const Route = createRootRoute({
   component: RootLayout,
@@ -29,6 +30,7 @@ function RootLayout() {
       <main className="mx-auto max-w-5xl px-6 py-8">
         <Outlet />
       </main>
+      <GrafanaFooterLink />
     </div>
   );
 }