test(security): Add comprehensive tests for crypto utilities

Commit notes

Tests for: - safeCompare: timing-safe string comparison - generateSecureToken: cryptographic random token generation - hashToken: SHA-256 token hashing - verifyTokenHash: combined hash verification

Also includes integration tests simulating: - Full token generation and verification workflow - Password reset token flow

Co-authored-by: armin.naimi <[email redacted]>