fix(cli): keep JSON argument failures machine-readable

[QiuLsG]

Problem and value

validate --json and deliver --json promise one JSON receipt on every failure, but argument parsing errors still used the human-only failure path: exit status 2, empty stdout, and plain-text stderr. This breaks callers that unconditionally parse stdout.

Closes #330.

Scope

• What changed: route validate --json and deliver --json argument failures through a versioned stage: "arguments" receipt; add stable CLI diagnostics for invalid or missing values, unknown options and diagram types, unsupported combinations, and usage errors; add table-driven regression coverage.
• What deliberately did not change: human-mode stderr, exit status 2, command signatures, renderer validation, diagram schemas, output geometry, and Viewer behavior.
• No unrelated changes: confirmed.

Stability impact

• Compatibility and migration risk: non-JSON behavior is unchanged. JSON callers now receive the documented parseable stdout instead of plain text for argument-stage failures.
• Renderer, validator, package, or generated-artifact risk: limited to CLI dispatch and the rebuilt Skill archive; no renderer, schema, example, or public-page changes.
• Failure behavior and rollback path: errors still occur before input reads or output writes and retain exit status 2. Reverting this commit restores the previous human-only argument error path.

Tests run

From archify/, each command passed with 1 target test, 0 failures:

• npx --yes node@18.20.8 --test --test-name-pattern "validate and deliver keep argument failures machine-readable with --json" test/cli.test.mjs
• npx --yes node@20.20.2 --test --test-name-pattern "validate and deliver keep argument failures machine-readable with --json" test/cli.test.mjs
• npx --yes node@22.23.2 --test --test-name-pattern "validate and deliver keep argument failures machine-readable with --json" test/cli.test.mjs
• npx --yes node@24.20.0 --test --test-name-pattern "validate and deliver keep argument failures machine-readable with --json" test/cli.test.mjs

Additional results:

• node --check archify/bin/archify.mjs: passed.
• git diff --check: passed.
• node --test test/cli.test.mjs: 40 passed, 1 failed, 3 skipped on each tested Node version on Windows. The sole failure is the existing installed-preview shutdown assertion: Windows reports { code: null, signal: "SIGTERM" } after the test sends SIGTERM, while the test expects a clean code 0 exit.
• Independent extracted-package smoke with Node 22: passed on Windows. Packaged validate --json and deliver --json argument failures both returned exit status 2, valid JSON stdout, stage: "arguments", and empty stderr.
• npm test: the brand-mark, validator, release-identity, golden-render, and new CLI regression checks passed; the overall Windows run exited 1 on existing platform/environment cases including unavailable symlinks, Bash not being on PATH, preview SIGTERM semantics, a Windows ESM drive-path fixture, and timing-sensitive notifier cases. The repository's full CI test matrix runs on Ubuntu; the Windows CI lane runs the package smoke exercised above.

Visual evidence

• Evidence provided: Not applicable; this changes CLI failure serialization only.
• Comparison conditions, when applicable: Not applicable.
• Automated or browser checks: deterministic CLI assertions and extracted-package smoke listed above.
• Perceptual visual review: Not applicable.

Generated artifacts

• Rebuilt archify.zip with the canonical Node 22 toolchain.
• No Gallery, guide, README proof, or example artifact changed because the patch does not affect rendering or public pages.

Checklist

• I used a minimal focused change and preserved existing typed JSON behavior unless the issue requires a contract change.
• I ran the relevant targeted tests and npm test in archify/.
• I added or updated a regression test for behavioral changes.
• I checked generated artifacts and package freshness when their sources changed.
• I removed secrets, private repository content, and customer data from fixtures and screenshots.