Constant PLUGIN_BODY_CAP_DEFAULT 

pub const PLUGIN_BODY_CAP_DEFAULT: u64 = _; // 1_048_576u64

The default body cap for plugin body phases on routes without an explicit limits.max_body_bytes (DW-157): 1 MiB, the same bound the nano-service body cap uses. Buffering must be opt-in (the plugin declaring the phase) and size-capped (always) — this is the cap when the route configures none.