Create Frontend Logging Redaction Helper

[edehvictor]

Summary

Add a frontend helper to redact sensitive values before logging errors or events.

Scope

• Redact tokens, private keys, auth headers, and wallet signatures.
• Support nested objects and arrays.
• Add tests for common sensitive key names.

Acceptance Criteria

• Logs no longer expose known sensitive fields.
• The helper can be reused across frontend error reporting code.