feat: Bedrock Guardrail configs support environment variable assignment

[entropic489]

Summary

Supports loading Bedrock guardrailConfig items from environment variables, using the existing extractEnvVariable() method.

Change Type

• New feature (non-breaking change which adds functionality)

Testing

I've added tests in the Bedrock initialize.spec.ts to ensure env var expansion is working as expected.

Test Configuration:

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes

[Copilot]

Pull request overview

Adds support for resolving ${ENV_VAR} placeholders inside Bedrock guardrailConfig entries during initialization, aligning guardrail configuration with existing env-var expansion behavior used elsewhere in the Bedrock setup.

Changes:

• Resolve guardrailIdentifier and guardrailVersion via extractEnvVariable() when guardrailConfig is provided.
• Add unit tests validating env-var expansion behavior (including whitespace and missing env var fallback) for guardrail config fields.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
packages/api/src/endpoints/bedrock/initialize.ts	Expands env-var placeholders for guardrail identifier/version when building llmConfig.guardrailConfig.
packages/api/src/endpoints/bedrock/initialize.spec.ts	Adds coverage for env-var expansion scenarios for Bedrock guardrail configuration.

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[Copilot]

To avoid duplicating the GuardrailConfiguration shape (and potentially dropping new fields if the type/API expands later), consider spreading the existing bedrockConfig.guardrailConfig and only overriding the resolved fields (guardrailIdentifier/guardrailVersion). This keeps behavior consistent if additional properties are added in the future.

Suggested change

	guardrailIdentifier: extractEnvVariable(bedrockConfig.guardrailConfig.guardrailIdentifier),
	guardrailVersion: extractEnvVariable(bedrockConfig.guardrailConfig.guardrailVersion),
	trace: bedrockConfig.guardrailConfig.trace,
	...bedrockConfig.guardrailConfig,
	guardrailIdentifier: extractEnvVariable(bedrockConfig.guardrailConfig.guardrailIdentifier),
	guardrailVersion: extractEnvVariable(bedrockConfig.guardrailConfig.guardrailVersion),

[Copilot]

The new env-var expansion tests are very similar and add a lot of repeated setup/assertions. Consider consolidating these into a parameterized test (e.g., it.each) and/or a small helper to set env + build params, to keep the spec file easier to maintain as cases evolve.