Function resolveCredentialValue

resolveCredentialValue<T>(requestValue, envValue, disableFallback): T | undefined
Resolves a single credential value by checking the request value first, then falling back to the environment value if allowed.
Type Parameters
- T
Parameters
- requestValue: T
  Value provided in the request (takes precedence)
- envValue: T
  Value from environment variable (fallback)
- disableFallback: boolean
  If true, don't use the environment value
Returns T | undefined
The resolved value, or undefined if not available
Example
```
const apiKey = resolveCredentialValue(
    credentials?.apiKey,           // From request
    process.env.SENDGRID_API_KEY,  // From environment
    credentials?.disableEnvironmentFallback ?? false
);
```
- Defined in Communication/base-types/src/CredentialUtils.ts:84