Build PAPER DESK: a private single-user trading terminal front end for Papertrade (papertrade.xyz), a synthetic perps exchange on HyperEVM priced at Hyperliquid's BBO mid, up to 1000x leverage. Static React + TypeScript + Vite app with lightweight-charts v5. It is ONLY a client of our own backend: every request goes to same-origin relative paths under /api; it must never call Papertrade, Hyperliquid or any third party directly, never load remote scripts, fonts or analytics at runtime (bundle IBM Plex Mono locally), never use eval or inline scripts, and never hold or ask for a private key, seed or wallet. Ship a strict Content-Security-Policy meta tag: default-src 'self'; connect-src 'self'; img-src 'self' data:; script-src 'self'; style-src 'self'.

Backend contract (implement a typed client in src/api.ts plus a mock mode: when VITE_MOCK=1 or ?mock=1, serve realistic synthetic data so the UI runs standalone):

GET /api/me -> {user, wallet, sessionKey:{address, expiresAt}, limits:{maxMarginUsd, maxLeverage}}

GET /api/markets -> [{instrumentId, symbol, mark, change24hPct, longOi, shortOi, maxLeverage}]

GET /api/candles?symbol=BTC&tf=15m&limit=1000 -> [{t,o,h,l,c,v}] with tf in 1m,5m,15m,1h,4h,1d

GET /api/account -> {equity, available, marginInUse, openPnl, queuedBalance}

GET /api/positions -> [{positionId, symbol, isLong, sizeUsd, marginUsd, leverage, entry, mark, pnlUsd, pnlPct, bustPrice, openedAt}]

GET /api/history?limit=200 -> closed trades with entry, exit, pnlUsd, fees, openedAt, closedAt

POST /api/orders/open {symbol, isLong, marginUsd, leverage, takeProfitPct?, stopLossPct?} -> {intentId, status}

POST /api/orders/close {positionIds:[...]} -> {intentId, status}

POST /api/orders/close-all -> {intentId, status}

GET /api/intents/:id -> {status: queued|confirmed|failed|reverted|expired|cancelled, error?}

WS /api/stream pushes {type:'mark'|'positions'|'account'|'intent', data}; auto-reconnect with backoff and show LIVE / RECONNECTING in the header.

Layout and look: Bloomberg terminal. Background #050607, primary orange #FF8C00, text #C7BCA6, profit #22c55e, loss #ef4444, IBM Plex Mono everywhere, zero border radius, dense tables, F1/F2 function-key style tabs (F1 TRADE, F2 POSITIONS & HISTORY, F3 ANALYSIS placeholder for future tools), keyboard shortcuts. Header strip: wallet (shortened), equity, available, margin in use, open PnL, session key expiry, connection state. TRADE tab: large chart left; right sidebar trade ticket (market BTC/ETH selector, long/short, margin USD, leverage slider 1-1000 with presets 10/50/100/250/500/1000, live bust-price and notional preview computed as notional = margin x leverage and bust = entry x (1 -/+ 1/leverage), optional TP/SL percent), a confirm step that restates side, size, leverage and bust price before sending, intent status toasts, and the open-positions table under the chart with per-row close and a guarded Close All.

Chart (port exactly, do not improvise): candlesticks with NO grid lines (vertLines and horzLines hidden), timeframe buttons 1m 5m 15m 1h 4h 1d, 160-bar initial zoom, crosshair readout. Bollinger Bands BB(15): SMA(15) midline in indigo #6366f1, and a sigma ladder at 1, 1.5 and 2 standard deviations (population sd over the same 15 closes), upper bands red shades and lower bands green shades, thin lines. Candle body color by where the close sits in the ladder: >= +2sd dark red #7f1d1d, +1.5..+2 red #dc2626, +1..+1.5 orange #f97316, mid..+1 amber #f59e0b, -1..mid lime #84cc16, -1.5..-1 light green #4ade80, -2..-1.5 green #16a34a, <= -2sd dark green #14532d. Signals at local extremes using a 5-bar lookback on each side: BUY when the bar low <= lower 1.5sd band (STRONG BUY at 2sd), SELL when the bar high >= upper 1.5sd (STRONG SELL at 2sd), drawn as series markers below/above bars. Declutter: within a same-side cluster (bars closer than 2 x lookback) only the most extreme signal keeps its text label, the rest show a bare arrow. Draw open-position price lines: entry grey solid, TP green, SL red, bust/liquidation hot pink #FF2D78 dashed only when within 35% of mark; add invisible anchor points so these lines never scroll off-scale. Put all indicator math in pure functions in src/indicators.ts with unit tests (vitest) covering SMA, population sd, band ladder values, candle color bucketing, signal detection and declutter on fixed fixtures.

Quality bar: responsive down to 1280px, no layout shift, guard chart resize and unmount races, format sub-penny and large numbers correctly, all money values as fixed-decimal strings. README documents the backend contract, mock mode, build and the CSP. No placeholder lorem text.