Function read 

pub fn read(text: &str) -> Result<Value, Diagnostic>

Reads a JSON document under the storage profile: no repeated object member, no more than MAX_DEPTH nested containers, and otherwise whatever serde_json accepts.

Grows onto a [READ_STACK_BYTES] stack via stacker::maybe_grow when the caller’s own stack is shallower than [RED_ZONE], so a document at the nesting ceiling answers nesting_too_deep rather than overflowing whatever stack the caller happens to be on — without paying for a spawned thread on every call, which matters here because the document-tree layout calls this once per file of a tree.