Add a faux/demo dashboard — preview the live UI with dummy data (pre-1.0)

[VijitSingh97]

Summary

Add a faux / demo dashboard to the site — a static, dummy-data replica of the Pithead
operator dashboard — so visitors can preview the live experience without cloning, syncing a node,
or owning hardware. This should ship before the 1.0 public launch (and stay maintained through
1.1 / 2.0 as the real UI evolves).

Why

The dashboard is the thing people screenshot and the strongest "show, don't tell" asset we have.
Today the homepage only shows a static screenshot (static/img/dashboard.png). A clickable,
believable demo:

• lets a prospective operator feel the product in 5 seconds, from a phone, with zero setup;
• de-risks the launch — people evaluate the real UI, not marketing claims;
• doubles as a living design reference while the Wave 3 dashboard work (pithead #156–#159) lands.

What

A self-contained /demo/ (or /preview/) page on the Hardrock site that visually reproduces the
real operational dashboard, populated entirely with plausible dummy data — no backend, no API,
nothing that phones home (keeps our "zero third-party requests" promise intact).

Approach

• Port the real dashboard's markup + styles from pithead
  (build/dashboard/mining_dashboard/web/templates/index.html + static/dashboard.css +
  pithead-mark.svg) into a Hugo layout here, so the demo is the real UI, not a re-drawn mock-up.
• Hard-code a realistic snapshot: live hashrate, sync progress, PPLNS window, per-worker table,
  P2Pool/XvB split, current tier + VIP status, share health, version badge.
• A clear, persistent "DEMO · dummy data" banner so it's never mistaken for a real instance.
• Link it prominently from the homepage — a "Preview the dashboard ↗" button on the Pithead
  project card (and/or the hero).

Acceptance criteria

• /demo/ renders the operational dashboard with believable dummy data, visually matching the real UI.
• Reuses the real dashboard's CSS (single source of truth — vendored/synced, not re-authored).
• Clearly labelled as a demo with fake data.
• Linked from the homepage (Pithead card / hero).
• Fully static, mobile-responsive, zero third-party requests, passes htmltest.
• Live before the 1.0 public launch.

Nice-to-have (later)

• Gentle "liveness": JS that ticks the hashrate / clock so it feels real (dummy data only).
• A Sync Mode variant (cf. static/img/syncing.png) toggled via a query param, to showcase first-boot.
• Light/dark toggle, mirroring the real dashboard's theme switcher.
• A short "what am I looking at?" annotation layer / guided callouts.

Out of scope

• Any real data source, websocket, or API. It is a static showcase only.

Tracking this now so it's not forgotten in the launch crunch — a pre-1.0 "go-live" item, not a v1.1 nicety.