Add a jsonText declaration to the contract command description: a
structured contract field is taken as one JSON text argument, decoded at
argv parsing, and admitted by the contract field's own schema, so
--schema advertises the contract's structure. This generalizes the
per-command producerLimitsOption wiring.
Migrate inspect-binary-layout and inspect-recorded-crash (producer_limits
as JSON text; recorded-crash keeps --debugger-context for
include_debugger_context) and delete their hand-written options and input
spreads.
The parity guard probes JSON-text fields with valid, malformed and
contract-refused JSON.