kEmbeddingHttpTimeout top-level constant

Duration const kEmbeddingHttpTimeout

The end-to-end deadline on one embedding HTTP round-trip. A black-holing endpoint (packets dropped, no fast connection-refused) must degrade to SemanticUnavailable like every other provider failure — never stall the whole search command behind the lexical half (the review committee's regression-risk finding on this diff; same bound-the-external-call convention as pr_describe.dart/bounded_use.dart).

Implementation

const Duration kEmbeddingHttpTimeout = Duration(seconds: 30);