Preserve SDK fatal behavior when adapting provider error schemas

When a provider changes its fatal error schema but a pinned SDK still reads a legacy field, adapt only the fatal handler and pass a fresh dictionary containing an allowlisted code into the existing SDK implementation. This preserves exception, receive-loop and reconnection semantics without copying the transport. Test actual JSON dispatch as well as the raised exception and pushed error; a helper-only test can miss downstream leakage. Normalize only explicitly supported code variants and use one bounded fallback for everything else. A schema example does not enumerate all codes or prove a timeout cause.

Applies when: an installed SDK such as Pipecat mismatches Deepgram Flux provider error fields. Keywords: Pipecat Deepgram Flux SDK fatal schema error allowlist receive diagnostics