Function validateNexusEnv

validateNexusEnv(logger?: ILogger): EnvValidationResult
Validates all NEXUS_* environment variables.
- Detects unknown vars (potential typos) with Levenshtein suggestions
- Detects invalid values for known vars
- Warn-only: never throws, never blocks startup
Parameters
- Optionallogger: ILogger
  Optional logger for direct warning output
Returns EnvValidationResult
Validation result with unknown and invalid var lists
- Defined in packages/nexus-agents/src/config/env-schema.ts:248