Support AWS Bedrock as an authentication provider

[AssahBismarkabah]

1Code strips CLAUDE_CODE_USE_BEDROCK from the environment in STRIPPED_ENV_KEYS_BASE, preventing users from authenticating through AWS Bedrock. The underlying @anthropic-ai/claude-code SDK supports Bedrock natively, but 1Code blocks it at the application level.

Request

Either:

1. Remove CLAUDE_CODE_USE_BEDROCK and CLAUDE_CODE_USE_VERTEX from STRIPPED_ENV_KEYS_BASE so the SDK can read them naturally
2. Or add a provider selection option in Settings (similar to how model selection already works) that allows users to choose betweendirect Anthropic API key, AWS Bedrock, or Google Vertex