PHP SDK 3.1.0

Adds optional workflow/query task spans, activity-attempt spans and Monolog correlation. Applications own OpenTelemetry providers, propagators, sampling, exporters and bounded shutdown. Default installs require no OpenTelemetry package.

Durable caller propagation activates only when Server discovery advertises the exact optional observability capability. Published Server 2.9.11 does not advertise it, so this verified combination uses independent task traces. Full Server and cross-SDK tracing delivery remains tracked in Workflow #773.

Qualification:

• All normal PHP/framework, corpus, analysis, package and documentation checks passed before the protected #199 merge. Release source is 222e27eddc0915957ad513dcc3b2b2418f5eb959; the entire merge tree equals the qualified candidate.
• Normal Packagist installation on PHP 8.3 with application-owned API 1.10.1 / SDK 1.15.0 completed a workflow through two independent worker processes against immutable Server 2.9.11. It produced four task/attempt spans and three correlated callback logs, preserved the result and original request ID, exited both workers with code zero and restored scope.
• A separate normal default installation on PHP 8.1.34 contained no OpenTelemetry API. Eight enabled/disabled controls preserved callback values, original exception identity and empty scope.
• Both consumers verified all 172 installed production files and the exact normal registry source/distribution references before and after execution. Temporary runtimes were removed.

The package retains PHP 3's fresh workflow-instance contract. Applications registering attributed handlers must use workflow classes or an explicit fresh factory, with transient PSR-11 bindings. See the package guide and Packagist release.