[BUG] Bedrock: model list ignores the selected region, and "cross-region" / "global" inference checkboxes are misleading

[LouisClt]

Describe the bug
The Bedrock model list is a static, hard-coded list, identical for every region and account. It does not show whether a model is available in the selected region, or whether it can only be used through an inference profile. It also misses models available on Bedrock today (e.g. Llama 4, Mistral Large 3, Nova Premier, Cohere Command R).

On top of that, the two Bedrock routing checkboxes have no description, and their labels suggest the opposite of what they do:

• "Use cross-region inference" sounds like requests may leave your area, so privacy-minded users (e.g. EU users under GDPR) leave it off. In reality it uses a geographic inference profile (eu., us., jp.…) that keeps processing within that geography. It is also required for recent models: Claude Sonnet 4.5, for example, supports no in-region inference at all, so with the box unchecked every request fails.
• "Use Global inference (auto-select optimal AWS Region)" sounds like a harmless performance option. In reality it routes requests to any commercial AWS region worldwide, and when checked it silently takes precedence over the cross-region option.

Nothing in the UI shows the model ID actually sent (anthropic.…, eu.anthropic.… or global.anthropic.…), and the error does not point to these settings.

To Reproduce
Steps to reproduce the behavior:

1. Select the Amazon Bedrock provider, region eu-west-3, with valid credentials.
2. Select anthropic.claude-sonnet-4-5-20250929-v1:0, leave both "Use cross-region inference" and "Use Global inference" unchecked.
3. Send any message.
4. The request is rejected by AWS, since this model has no in-region support (see the AWS model card below).

Expected behavior

• The model list reflects what is available in the selected region, and indicates when a model requires an inference profile.
• Each checkbox has a short description of where requests are processed (geography vs worldwide) and when it is required.
• The error for a model that needs an inference profile suggests enabling cross-region inference.

Screenshots

Video

What version of zoo are you running
3.82.1

Additional context

• AWS documentation for Claude Sonnet 4.5 lists no in-region support in any region, only Geo (us., eu., au., jp.) and Global inference IDs: https://docs.aws.amazon.com/bedrock/latest/userguide/model-card-anthropic-claude-sonnet-4-5.html
• AWS recommends Geographic cross-region inference for data residency requirements, and describes Global as routed worldwide: https://docs.aws.amazon.com/bedrock/latest/userguide/cross-region-inference.html
• The model list comes from the static bedrockModels table (packages/types/src/providers/bedrock.ts), with no region filtering. Models currently offered by Bedrock: https://docs.aws.amazon.com/bedrock/latest/userguide/model-cards.html
• The prefix is added at request time in getModel() (src/api/providers/bedrock.ts); Global is applied first, cross-region only otherwise.
• Related: [ENHANCEMENT] Improve Amazon Bedrock model discovery, context handling, and output limits #124 / [Bedrock] Discover foundation models and inference profiles #310, which propose discovering available models and inference profiles through the AWS API (no progress since May).