fix(bedrock): guard against null url in image_url parts and lifecycle status (#55686)

[hashbender]

Summary

Prevent AttributeError crash when Bedrock Converse encounters an image_url part with a null url field, or a model lifecycle entry with a null status.

Problem

Two .get(key, "") patterns crash when the key exists with value None:

1. image_url.get("url", "") returns None (not "") when url is explicitly null → url.startswith("data:") raises AttributeError: 'NoneType' object has no attribute 'startswith'

2. lifecycle.get("status", "").upper() returns None when status is null → .upper() raises AttributeError

The dict.get(key, default) default only applies when the key is absent, not when it is present with value None.

Fix

Use (x.get("key") or "") which coalesces both absent-key and None-value to empty string:

• image_url.get("url") or "" — null URL parts are safely skipped (empty string doesn't match data: prefix)
• lifecycle.get("status") or "" — null status is treated as non-ACTIVE (model skipped)

Fixes NousResearch#55686

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Mirror-of: NousResearch#55996
NousResearch#55996

[tenki-reviewer]

Review Complete
No issues found!

Risk: 🟢 Low (12/100) — no findings · 4 LOC across 1 file

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This PR patches two sites in agent/bedrock_adapter.py where dict.get(key, default) can propagate None instead of the default when the Bedrock API returns a key with a null value. A third instance of the same pattern was identified in the same function but fell below the confidence threshold.

Files Reviewed (1 files)

agent/bedrock_adapter.py