[Low] --chain all works but is completely undocumented

[Nicolai1205]

Summary

--chain all is a valid value that returns cross-chain results, but it appears nowhere in the CLI help, README, or schema. It is only discoverable from API error messages when passing an invalid chain.

Discovery

nansen research smart-money netflow --chain fakechain

The error message lists valid chains including 'all':

Valid options are: 'all', 'arbitrum', 'avalanche', 'base', ...

nansen research smart-money netflow --chain all --limit 2  # works, returns cross-chain results

Impact

Low but useful. Cross-chain queries are a common pattern. Agents and users who don't know all exists will make per-chain calls and aggregate manually.

Fix

Add all to the chains list in schema.json and document it in the README and relevant --help text.

Found during

Clawfooding session on v1.10.1. Referenced in PR #167.