test(api): add unit tests for sessionExpiredError module (closes #1194)

[rupesh-kumar-sah]

Overview

Closes #1194.

Adds comprehensive unit tests for in .

Coverage Details

• ****: Confirms exported constant value matches expected .
• ****:
  • Validates full payload extraction (, , ) from with nested response data.
  • Tests fallback to when is missing.
  • Tests fallback to and default message when no error details are provided.
  • Tests handling of standard instances returning sanitized .
  • Tests edge cases: non-error objects, strings, numbers, , and .
• ****: Verifies returned sanitized error contract.

Verification

• Tested locally with Jest: all 7 unit tests pass cleanly.
• ESLint and Prettier verified with 0 errors and 0 warnings.