ModelRouterLanguageModel hardcodes specificationVersion = "v2" regardless of what the underlying model actually is. The gateway returns a v3 model (from .responses()), but Mastra thinks it's v2.type: "provider"type: "provider-defined"type: "provider-defined". AI SDK v6 rejects this unrecognized type, so the tools array ends up empty.packages/core/src/llm/model/router.ts#L80 - ModelRouterLanguageModel hardcodes specificationVersion = "v2"packages/core/src/stream/aisdk/v5/compat/prepare-tools.ts#L128 - uses targetVersion to decide tool type format