cppcheck reports returnByReference on XModemAdapter::getForPhone():
`meshtastic_XModem` carries a 128-byte payload buffer plus header fields,
so returning it by value copied the whole struct on every call.
Return `const meshtastic_XModem &` instead, and mark the method const -
it is a pure read of xmodemStore, with resetForPhone() being what drains
it. Every caller either copies into a value or reads a single field, so
no call site changes.
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
Co-authored-by: Tom <116762865+NomDeTom@users.noreply.github.com>
