Function is_browser_only_lowering 

pub fn is_browser_only_lowering(name: &str) -> bool

★ WHICH SYNTHESIZED FUNCTIONS NEED A DOCUMENT — the one place the answer lives.

A component lowers into two families. __html_<Name> builds a string out of htmlEscape and +, which is ordinary code on any tier. __render_, __act_, __mount_, __bind_, __patch_, __dir_, __cb_ and the __lgx_* dispatcher and page drivers call createElement and appendChild — a browser’s document, which a server binary does not have.

Emitting the second family into AOT-Rust is what made the component model look unshippable, and the blanket refusal that followed meant per-request server rendering did not exist in production: markup could only be produced at BUILD time by pre-rendering, so nothing whose content depends on the request could be server-rendered at all.

The names are MINTED HERE, by the functions directly above, so this is where the question is answerable without guessing. A backend asking “is this browser-only?” by matching strings of its own would be a second spelling of a decision only this module makes.