Description

When users configure api_mode: anthropic_messages for custom endpoints, _try_custom_endpoint() always defaults to the OpenAI SDK, ignoring the api_mode setting. This causes vision_analyze and other auxiliary tasks to fail with "Your request was blocked" on Anthropic-compatible endpoints.

Expected Behavior

Custom auxiliary endpoints should respect the api_mode configuration and use AnthropicAuxiliaryClient when api_mode: anthropic_messages is specified.

Actual Behavior

All custom endpoints use the OpenAI SDK regardless of the api_mode setting, causing failures on Anthropic-compatible endpoints.

Fix

Resolved in #7648