A generous default upper bound (16 MiB) on a single inbound JSON-RPC line for
the stdio transport, guarding against unbounded line accumulation: a peer that
never sends a newline would otherwise grow the read accumulator without limit
(a memory-exhaustion DoS). runStdio and spawnStdioTransport accept an
override; pass size_t.max to effectively disable the bound.
A generous default upper bound (16 MiB) on a single inbound JSON-RPC line for the stdio transport, guarding against unbounded line accumulation: a peer that never sends a newline would otherwise grow the read accumulator without limit (a memory-exhaustion DoS). runStdio and spawnStdioTransport accept an override; pass size_t.max to effectively disable the bound.