Platform trading volume — total turnover routed through your builders, by venue

How much trading volume your platform routed over `[from, to)`, split by venue (Hyperliquid + Polymarket). Always platform-scoped: every fill is attributed through a builder you registered (portal → Wallets → Platform Attributions), so this is *your platform's* turnover, not a single wallet's activity. `volumeUsd` = notional USD; `builderFeeUsd` = the fee the venue credited your platform (**Hyperliquid only** — Polymarket per-fill fees aren't tracked, so it's `null` there); `tradeCount` = attributed fills; `walletCount` = your registered wallets of that venue with ≥1 attributed fill. **Hyperliquid** numbers come from HL's authoritative per-builder export (lags real time by ~1–2 days); **Polymarket** from on-chain fills (real time). Returns `400 no_platform_attribution` when you have no registered builder. `from`/`to` are ISO-8601 (omit for all-time).