auto-triage: catch TypeError from malformed RAST server error response

[jplfaria]

Summary

Fixes ModelSEED/modelseed-api-ops#19

Root cause

When the RAST annotation server (tutorial.theseed.org) returns an error response where err["error"] is a plain string instead of the expected {"code":..., "message":...} dict, the rpcclient.py line:

raise ServerError(**err["error"])  # line 75

raises TypeError: ServerError() argument after ** must be a mapping, not str.

This TypeError escapes genome_annotator.py's except Exception as exc: block because:

• The except block does catch it
• But is_transient is False (no HTTP status codes in the TypeError message)
• So it re-raises the raw TypeError, giving Celery workers a misleading internal Python error

Fix

Add a except TypeError as exc: handler before the general except Exception in annotate_fasta()'s retry loop. It converts the raw TypeError into a descriptive RuntimeError so the Celery failure log and job error field show a meaningful message.

Files changed

• src/modelseed_api/services/genome_annotator.py: Add TypeError handler
• tests/unit/test_genome_annotator.py: Add TestAnnotateFastaTypeErrorHandling regression test

Test plan

• Unit test test_rpc_typeerror_wraps_to_runtimeerror passes (mocks RPCClient to raise TypeError, verifies RuntimeError with "malformed error response" is raised)
• Existing genome annotator unit tests still pass