fix(vision): respect auxiliary vision routing

[felix-windsor]

Summary

• stop vision_analyze from passing stale AUXILIARY_VISION_MODEL values as explicit model overrides
• let browser_vision rely on call_llm(task="vision") so auxiliary.vision provider/model/base_url/api_key resolve together
• update regression tests around stale env bridges and browser screenshot vision routing

Fixes #24842

Tests

• scripts/run_tests.sh tests/tools/test_vision_tools.py tests/tools/test_browser_console.py tests/tools/test_vision_native_fast_path.py tests/agent/test_vision_resolved_args.py tests/agent/test_auxiliary_config_bridge.py
• .venv/bin/ruff check tools/vision_tools.py tools/browser_tool.py tests/tools/test_vision_tools.py tests/tools/test_browser_console.py tests/agent/test_auxiliary_config_bridge.py

[alt-glitch]

Competing fix for #24842 — also see #24872 which addresses the same vision config routing issue with a simpler env-var-then-config fallback approach.

[felix-windsor]

Rebased on latest main (as of 2026-05-18) and force-pushed.

Local verification:

• ./scripts/run_tests.sh tests/tools/test_vision_tools.py

(Still seeing no CI statuses reported on the PR head; may need maintainer Actions approval for fork PRs.)

[teknium1]

Thanks for isolating the stale browser model override; that path remains real on current main: tools/browser_tool.py:4103 reads AUXILIARY_VISION_MODEL and :4140-4144 forwards it explicitly, while agent/auxiliary_client.py:5866-5902 gives explicit models precedence over auxiliary.vision.

Problems

• The vision_analyze change removes the environment-only compatibility override. AUXILIARY_VISION_MODEL remains documented at website/docs/reference/environment-variables.md:801, and current coverage at tests/tools/test_vision_tools.py:220-238 asserts that it is forwarded. The task-config helper reads config only (agent/auxiliary_client.py:5996-6037), so passing None does not preserve this fallback.

Suggested changes

• Keep config authoritative while retaining environment-only fallback, either in a shared resolver or with config-first resolution at the tool boundary.
• Cover both config-vs-stale-env precedence and env-only compatibility through the real auxiliary resolution path.

Automated hermes-sweeper review.

[teknium1]

Passing None unconditionally removes the documented environment-only AUXILIARY_VISION_MODEL override. Please retain it as a fallback when auxiliary.vision.model is unset, while making config win when both are present.