Derive exported batching flags from the server's batching options

[glen-84]

Summary

• SchemaFileExporter now writes variableBatching and requestBatching in the generated schema-settings.json from the schema's GraphQLServerOptions.Batching instead of declaring both as true. aliasBatching stays true, since it needs no server support.
• A source schema that does not call AddSourceSchemaDefaults(), or otherwise allow batching, therefore exports false for both flags, and a gateway composed from that file sends one request per item instead of a variable batch the server rejects with Invalid GraphQL Request. (HC0009).
• The lookup goes through a small internal ITransportCapabilitiesProvider in Core, implemented in HotChocolate.AspNetCore on top of IOptionsMonitor<GraphQLServerOptions>, so the command-line project keeps its Core-only dependency. Without a registered provider the exporter keeps writing true for both flags.

Test plan

• New SchemaFileExporterTests cover the fallback without a provider and that provider values are written through to the settings file.
• New TransportCapabilitiesProviderTests cover no batching, AddSourceSchemaDefaults(), a single allowed flag, and per-schema-name resolution.
• Existing SchemaExportCommandTests pass with unchanged snapshots.

[Copilot]

🟡 Changes recommended

Re-exporting an existing settings file will not update variableBatching/requestBatching because the current update path only rewrites the top-level name, leaving stale batching flags behind.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR updates schema export so that the generated *-settings.json accurately reflects which batching modes a subgraph server actually allows, preventing gateways from emitting batching requests a server will reject (e.g., HC0009).

Changes:

• Derive exported variableBatching / requestBatching from server-side batching configuration via an internal ITransportCapabilitiesProvider (with a default fallback when absent).
• Add an ASP.NET Core implementation (TransportCapabilitiesProvider) backed by named GraphQLServerOptions and register it in DI.
• Add new tests for both the exporter behavior and the provider’s mapping logic, plus a small doc update.

File summaries

File	Description
website/content/docs/fusion/batching.md	Documents that exported batching flags mirror server batching options (except aliasBatching).
src/HotChocolate/Core/test/Types.Tests/Execution/Internal/SchemaFileExporterTests.cs	Adds exporter tests for provider fallback and capability passthrough.
src/HotChocolate/Core/src/Types/Execution/Internal/TransportCapabilities.cs	Introduces an internal capability model for exporter batching flags.
src/HotChocolate/Core/src/Types/Execution/Internal/ITransportCapabilitiesProvider.cs	Adds internal abstraction used by the exporter to obtain capabilities.
src/HotChocolate/Core/src/Types/Execution/Internal/SchemaFileExporter.cs	Uses provider-derived capabilities when writing new settings files.
src/HotChocolate/AspNetCore/test/AspNetCore.Tests/TransportCapabilitiesProviderTests.cs	Adds mapping tests for server options → transport capabilities (including multi-schema).
src/HotChocolate/AspNetCore/src/AspNetCore/TransportCapabilitiesProvider.cs	Implements capability lookup using IOptionsMonitor<GraphQLServerOptions>.
src/HotChocolate/AspNetCore/src/AspNetCore/Extensions/HotChocolateAspNetCoreServiceCollectionExtensions.cs	Registers the provider so exports can reflect per-schema server settings.

Review details

• Files reviewed: 8/8 changed files
• Comments generated: 1
• Review effort level: Lite

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[github-actions]

Patch coverage

100.0% of changed lines covered (26/26)

File	Covered	Changed	Patch %
…/HotChocolateAspNetCoreServiceCollectionExtensions.cs	3	3	100.0% 🟢
…/AspNetCore/src/AspNetCore/TransportCapabilitiesProvider.cs	8	8	100.0% 🟢
…/Core/src/Types/Execution/Internal/SchemaFileExporter.cs	13	13	100.0% 🟢
…/Core/src/Types/Execution/Internal/TransportCapabilities.cs	2	2	100.0% 🟢

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Project coverage: 57.9% (288083/497753 lines)