e0a28abbcd
When model != DEFAULT_EMBEDDING_MODEL, generate_embedding now calls client.embed(text, model=model) and wraps the returned vector in an EmbeddingResult tagged with the requested model. On any exception (NotImplementedError from providers without an embeddings endpoint, transient network errors, etc.), the existing T107 warning fires and the function falls back to the zero-vector sentinel — callers detect model == 'fallback' and skip indexing. Adds: - MockLLMClient accepts a canned_embeddings queue mirroring the existing canned pattern. embed() pops from the front; empty queue raises IndexError so misconfigured tests fail loudly. - Settings.embedding_model defaults to "pseudo-sha256-384" so existing zero-config installs keep Phase 4 behavior. The app lifespan now passes this through to EmbeddingWorker.model. The public signature of generate_embedding is unchanged: (client, *, text, model=DEFAULT_EMBEDDING_MODEL, dim=..., timeout_s=...).