fix: make JSON capture preflight side-effect free

[codeforester]

Summary

• Inspect Click option arity with its raw parser rather than creating and closing resilient contexts, avoiding duplicate consumer callbacks, callable defaults, type conversions, lazy resolution, and close hooks.
• Preserve deferred callable-default behavior and nested default-map, auto-envvar, root/leaf, and negated-flag precedence.
• Keep flag-like option values as human output, including multi-value options, attached short values, and -- positional data.

Validation

• Full pytest suite passed.
• Repository-wide Ruff, format, mypy, generated API reference, and diff checks passed.

Fixes #338
Fixes #339

[codeforester]

Correctness (reproduced): when a Click parse/validation error occurs before the leaf command's wrapper runs, the deferred JSON-capture fallback uses the stale preflight guess instead of the value Click's real parse already computed, silently downgrading a JSON-configured invocation to plain-text output. Reproduced: a subcommand with a required argument, invoked without it and without an explicit --json flag, emits a plain-text usage error instead of the base-cli.error JSON envelope main correctly produces for the same scenario.

[codeforester]

Correctness (reproduced): the subcommand-walk in _click_lifecycle_value sets the child Click Context's info_name to the literal, unnormalized command-line token instead of the name Click's own resolve_command would use after token_normalize_func. With a group using token_normalize_func=str.lower and a default_map keyed by canonical name, invoking with a differently-cased token makes the preflight miss the default_map entry and return a firm-but-wrong False, causing output_capture to be set to None (no capture) while the real parse later resolves json=True — real stdout leaks to the terminal outside the JSON envelope.

[codeforester]

Efficiency: run_app now unconditionally runs the full Click-parser-based preflight (_click_lifecycle_value, which builds a click.Context and calls get_params/make_parser().parse_args() per nested command level) twice per invocation with identical args/command/default_map — the two calls always produce the same result, so the first pass is pure waste. main only performed this resolution once, often skipped via a cheap fast path.