fix(vision): resolve Nous vision model correctly in auto-detect path

[Ifkellx]

Problem

The vision auto-detect chain calls resolve_provider_client() with the vision model from _PROVIDER_VISION_MODELS, but resolve_provider_client() always called _try_nous() without vision=True. This caused it to return the default text model instead of the vision-capable xiaomi/mimo-v2-omni, resulting in 404 errors from the Nous inference API when sending images.

Additionally, _PROVIDER_VISION_MODELS was missing an entry for the nous provider.

Root Cause

The auto-detect path in resolve_vision_provider_client():

1. Looks up _PROVIDER_VISION_MODELS.get("nous") → returns xiaomi/mimo-v2-omni
2. Calls resolve_provider_client("nous", model="xiaomi/mimo-v2-omni")
3. resolve_provider_client calls _try_nous() without vision=True
4. _try_nous() ignores the passed model, returns the default text model

The fallback path (_resolve_strict_vision_backend) worked correctly because it called _try_nous(vision=True) directly.

Fix

1. _PROVIDER_VISION_MODELS: Added "nous": "xiaomi/mimo-v2-omni" entry so the vision auto-detect chain picks the correct multimodal model.

2. resolve_provider_client: Auto-detects vision tasks by checking if the requested model matches a value in _PROVIDER_VISION_MODELS or is a known vision model name, then passes vision=True to _try_nous().

Verification

• xiaomi/mimo-v2-omni returns HTTP 200 with image inputs on Nous inference API
• google/gemini-3-flash-preview returns 404 with image inputs on Nous inference API
• Free tier Nous accounts: only Xiaomi models are available, making this fix essential

Impact

Fixes browser_vision and vision_analyze tools for all Hermes users on Nous (both free and paid tiers).

[teknium1]

Merged via PR #13699 (#13699) — your commit was cherry-picked onto current main with your authorship preserved in git log (commit 0301787). Thanks for the fix! Pairs with #13682 (@helix4u) which landed minutes earlier and fixes the stale-credential side of the same vision report Tom-in-Tampa filed.

[alt-glitch]

Duplicate of #13699 — salvaged and merged as #13699 by teknium1.