Always preserve positional syntax invariants with property tests

When changing CLI introspection or documentation generation, maintain exact positional rendering invariants and encode them in property-based regressions. Array positionals must always remain variadic and include ...; determine required versus optional syntax independently from variadicity, using positive minimum cardinality for <name...> and absent minimum for [<name...>]. Extracted placeholders should exclude the ellipsis while metadata keeps variadic: true. Tuple positionals must always use angle-bracket placeholders, rendering required values as <name> and optional values as [<name>], with deterministic fallback names. Ensure generated signatures and argument tables use the same canonical formatter rather than duplicate logic.