fix(auxiliary): support named custom providers in auxiliary tasks / 辅助任务支持命名自定义 provider

[WenhuaXia]

Summary / 概述

辅助任务现在可以正确解析命名自定义 provider（custom:name），修复了 vision（图像识别）、goal_judge 等任务在使用自定义 provider 时静默失效的问题。

Auxiliary tasks can now correctly resolve named custom providers (custom:name), fixing silent failures in vision, goal_judge, and other tasks when using custom providers.

Root Cause / 根因

_normalize_aux_provider() would strip custom:qwen → custom, forcing all named custom providers through the anonymous-custom path (reads model.base_url + OPENAI_API_KEY from env). Users with custom_providers in config but no OPENAI_API_KEY env var set would get broken auxiliary tasks.

_normalize_aux_provider() 会把 custom:qwen 强制 strip 成 custom，导致所有命名自定义 provider 都走匿名 custom 路径（读环境变量 OPENAI_API_KEY）。如果用户没设置这个环境变量，辅助任务就静默失败。

Changes / 改动

1. Remove the early return in _normalize_aux_provider() — custom:name is now preserved intact so resolve_provider_client can route through the named-custom-provider branch, which reads from custom_providers in config.yaml.

   移除 _normalize_aux_provider() 中 strip custom:name 的 early return。resolve_provider_client 现在可以正确走 named custom provider 分支，从 custom_providers 读取 base_url + api_key。

2. Add fallback in _resolve_custom_runtime() — when requested="custom" falls back to OpenRouter (because no bare custom entry exists), try resolve_runtime_provider(requested=None) to pick up the user's actual main provider as a safety net.

   在 _resolve_custom_runtime() 增加 fallback：当 custom 回退到 OpenRouter 时，尝试用 requested=None 重新解析用户实际的主 provider 作为兜底。

Affected Tasks / 影响范围

Any auxiliary task that uses custom:name as provider:

• vision (image recognition / 图像识别)
• goal_judge (automatic goal continuation / 目标自动延续)
• compression, web_extract, etc.

所有使用 custom:name 作为 provider 的辅助任务：

• vision（图像识别）
• goal_judge（目标自动延续）
• compression、web_extract 等

Testing / 测试

All existing tests pass (32 tests in test_auxiliary_client.py + test_auxiliary_named_custom_providers.py).

所有已有测试通过（test_auxiliary_client.py + test_auxiliary_named_custom_providers.py 共 32 个测试）。

Related: #37182

[teknium1]

Thanks for tracing the named custom-provider failure mode. This is now covered on current main by a later auxiliary-routing fix, so this PR is redundant.

• Automated hermes-sweeper review verified agent/auxiliary_client.py:4227-4255: custom:<name> main providers pass their resolved runtime endpoint and credentials into auxiliary routing.
• agent/auxiliary_client.py:4632-4695 builds the custom auxiliary client from those explicit values instead of falling back through bare custom resolution.
• Commit 92da7a9970548340f0d538ef94d7af543d1dc7a5 (fix(auxiliary): reuse main_runtime credentials for named custom providers) implemented this behavior and is contained in release v2026.7.7.
• Regression coverage is present in tests/agent/test_auxiliary_named_custom_providers.py:496-563.

Closing as implemented on main.