fix(hydra): stream totalItems as an integer

[soyuka]

One of three PRs finishing the 4.3 CI unblock started in #8458. This is the only one that changes runtime behaviour, which is why it is split out.

Problem

Hydra\Collection::$totalItems was declared float (src/Hydra/Collection.php:34). symfony/json-streamer 8.1.4 (released 2026-08-01) began encoding with JSON_PRESERVE_ZERO_FRACTION — see upstream commit 57ff6c1 "[JsonStreamer] Use readable JSON encode defaults", now at vendor/symfony/json-streamer/Write/PhpGenerator.php:43-44. A float 10.0 therefore serialises as 10.0 instead of 10.

That output contradicts two contracts this project publishes for the same field:

• src/Hydra/JsonSchema/SchemaFactory.php:172-173 — 'type' => 'integer', 'minimum' => 0
• src/JsonLd/HydraContext.php:606-609 — 'range' => 'xsd:integer'

It also diverged from the non-streamed path: src/Hydra/Serializer/CollectionNormalizer.php:66 passes the same value through plain json_encode (no PRESERVE_ZERO_FRACTION), emitting 10. The streamed and normalised representations of one resource disagreed.

Fix

Narrow the property to int and cast at the assignment site in src/Hydra/State/JsonStreamerProcessor.php:94. The float originates from PaginatorInterface::getTotalItems(): float (src/State/Pagination/PaginatorInterface.php:36), which is unchanged.

Hydra\Collection is marked @internal (src/Hydra/Collection.php:21), so narrowing the property type is not a BC break.

Effect

Streamed JSON-LD collections emit "hydra:totalItems": 10 rather than 10.0, matching the published JSON Schema, the JSON-LD context, and the non-streamed output.