chore: upgrade Utopia Client to ^0.4

[ChiragAgg5k]

Summary

Upgrade utopia-php/client to ^0.4, without a dual range or version alias. Refresh the tracked lockfile to Client 0.4.3 and PSR-7 0.2.2. Stripe APIs, transport injection, and retry behavior are unchanged.

A release is needed after merge before downstream applications can resolve this constraint.

Verification

• vendor/bin/phpunit --filter 'InvoiceTest|CreditTest|DiscountTest': 45 tests, 187 assertions passed on PHP 8.5.10, with Client 0.4.3 installed.
• composer lint, Composer validation, and git diff --check: passed. The locked formatter emitted PHP deprecation messages.
• Blocked: composer check crashes in the locked PHPStan's BetterReflection code on PHP 8.5: ReflectionClassConstant::IS_PUBLIC has an incompatible constant type. A separate run using the monorepo's newer PHPStan reports 46 source/test typing errors; that is not a passing analysis result. No toolchain/source fixes are bundled here.
• Live Stripe tests and the webhook fixture requiring a secret were not run. No live payment requests were made; the tests above do not constitute end-to-end Stripe verification.
• Composer reported no security advisories. Dependency installation used --ignore-platform-reqs.

No screenshots apply to this dependency-only backend change.

[greptile-apps]

Confidence Score: 4/5

The dependency resolution appears internally consistent and no concrete runtime incompatibility was found, but deterministic transport-level regression coverage should be added.

Findings

1.  Transport Coverage Is Missing ▶

Summary

• Keeps the root PSR-7 constraint at ^0.2.
• Updates the corresponding package references, metadata, and lockfile content hash.
• Lacks deterministic behavioral coverage of the upgraded production transport boundary.