FEAT: AI Shell, allow claude bedrock (and sso)

**Is your feature request related to a problem? Please describe.**
I'd like to use claude with bedrock as we are only allowed to use bedrock for company data

**Describe the solution you'd like**
Allow claude bedrock usage like claude code does (e.g. https://docs.anthropic.com/en/docs/claude-code/amazon-bedrock)

**Describe alternatives you've considered**
not using ai shell

