The flag description is inconsistent across the four files introduced or modified by this PR: `docs/cli/server.md` and `internal/cli/server/flags.go` say RPC queries for 'pending' will 'return an error', while `docs/cli/example_config.toml` and the `config.go` comment say they will 'return nil'. In practice both are partially correct: `eth_getBlockByNumber('pending')` returns null (nil) when the pending block is absent, while `eth_getBlockReceipts` returns an explicit error string—so neither des