Show the psnr reported by optimize and convert - #45

Two independent reviews, one by a Claude agent and one by codex (gpt-5.6-sol, read-only). Both approve the behavior; codex requested one change (locale-dependent formatting). Addressed in commit d39c2fd, followed by both reviews.

What was addressed

• Locale, codex medium. The human summary used sprintf('%.2f', ...), which prints a comma decimal under a non-C LC_NUMERIC. Switched to %.2F (locale-independent), so the output is always PSNR 41.27 dB.
• Per-command contract, both raised as minor. Resize and thumbnail had no --json test, so the "no psnr key" promise held only transitively through the shared emit(). Added an exact-match --json test on the resize command and a "no PSNR in the human summary when null" assertion on convert.

Left as noted follow-ups (not this PR): the SDK-version bump means CI stays red until glimpse-php v3.1.0 is tagged and the lock is refreshed (composer update mathiasgrimm/glimpse-php); the - stdout/STDERR routing has no test, but that gap predates this change and the PSNR path takes the same branch.

Claude review

Verdict: clean and correct; approve once glimpse-php v3.1.0 is tagged and the lock is refreshed.

What I verified

• emit() correctness. JSON: psnr is appended after height only when non-null, using a strict !== null check, so a legitimate 0.0 still emits. Human summary: the suffix renders inside the existing parentheses and collapses to an empty string when null, so pre-PSNR output is byte-identical. The - output routing is untouched: both payload and summary are built before the STDERR-vs-line ternary, so PSNR flows identically to the STDERR path (metadata must not corrupt the image bytes on STDOUT).
• Tests lock all three JSON states: psnr present (strict toBe including the key), explicit "psnr": null, and key absent (the pre-existing strict toBe). The human summary is locked with the full parenthesized string for both convert and optimize.
• Suite: composer test passes against the patched vendor SDK: Pint clean, PHPStan clean, 288 tests / 800 assertions.
• Constraint bump ^3.1 is right; ImageResult->psnr first exists in 3.1.

Findings

• Minor: the "resize/thumbnail unchanged" claim is only locked transitively. Neither resize nor thumbnail has a --json test, and their summary assertions are prefix-only. One strict toBe JSON test on resize would pin the per-command contract.
• Minor: the - output branch of emit() has no test (predates this PR).

Codex review

Verdict: Changes requested. The JSON behavior and STDERR routing are correct, but human output is locale-dependent.

Medium

• app/Commands/GlimpseCommand.php uses locale-aware %.2f. Under LC_NUMERIC=de_DE.UTF-8, this renders PSNR 41,27 dB instead of the documented PSNR 41.27 dB. Use %.2F or another locale-independent formatter.

Low

• Convert tests only exercise file output. No test invokes --output=-, where image bytes must stay on STDOUT and metadata on STDERR. The implementation is correct but this binary-stream contract is unprotected.

Minor notes

• JSON output preserves the existing shape and conditionally adds a numeric psnr key only when non-null.
• The explicit JSON null-omission test is good. Consider also asserting the human output contains no PSNR when null.
• Resize and thumbnail tests only check a summary prefix; exact assertions would better protect the "unchanged" promise.
• The ^3.1 constraint is the correct minimum.
• Local verification passed: 288 tests, 800 assertions, plus Pint and PHPStan.