Add PHP state management quickstart (http + sdk) #1345

Describe the feature

Follow-up to #1341: add state_management/php/{sdk,http}, mirroring the python quickstart — a single order-processor CLI app that loops saving, getting, and deleting order state in the shared redis statestore.

• sdk: DaprClient::saveState() / getState() / deleteState()
• http: raw POST/GET/DELETE /v1.0/state/statestore via curl

Dependency

Building this surfaced an upstream SDK bug: DaprClient::deleteState() fatals with a TypeError in the published dev-main (null etag passed to a non-nullable parameter) — dapr/php-sdk#153, fixed by dapr/php-sdk#154. Until that merges, the sdk variant cannot be validated by CI and no composer.lock is committed for it. The http variant has no third-party dependencies and validates as-is.

Both variants pass make validate locally today (sdk validated against dapr/php-sdk@fix-delete-state-etag).