[Feature Request] Expose LLM extra parameters in the AI settings UI

[Tranquillius]

Description

Please add PAPERLESS_AI_LLM_EXTRA_PARAMS as a field in the AI settings UI, next to the backend, endpoint and model fields.

Some models reject the default temperature. With claude-sonnet-5 and claude-haiku-5-5 on the OpenAI-compatible Anthropic endpoint, AI suggestions fail with a 502 and the log shows:

Error code: 400 - {'error': {'code': 'invalid_request_error', 'message': 'temperature is deprecated for this model.', 'type': 'invalid_request_error', 'param': None}}

Setting PAPERLESS_AI_LLM_EXTRA_PARAMS='{"temperature": 1}' fixes this. Because it is environment-only, users who configure everything in the UI have to edit their compose file and restart the container. The failing request also gives no hint that this setting exists.

This does not ask Paperless-ngx to support specific models or keep a per-model list. Users could handle such cases themselves from the UI.

Other

Related, closed as not a bug: paperless-ngx/paperless-ngx#13399, paperless-ngx/paperless-ngx#13803, paperless-ngx/paperless-ngx#13878. In paperless-ngx/paperless-ngx#13399 a configurable temperature was mentioned as a possible future option.

Tested on 3.4.1, Docker official image. claude-haiku-4-5 and claude-sonnet-4-6 work without the setting.