Tape imbalance

Server-side time-bucketed rollup of the options tape. One row per bucket so long windows stay small.

`weight`	Meaning
`flow` (default)	Multi-venue aggressive premium by call/put × buy/sell, plus passive
`delta`	Customer BS delta notional (HIRO-style). Deribit-quality prints for IV/units

Each point includes net and cumulative_net so you can plot a running line without another pass. Coins: BTC, ETH.

See also