fix: contextualize email redaction in audit logs and error reports

[AbuJulaybeeb]

What was done

Removed email from the global SENSITIVE_KEYS list and Pino logger redact paths in src/lib/logging/index.ts.
Implemented targeted email redaction inside the src/app/api/errors/report/route.ts handler to protect deeply nested PII.
Applied contextual email redaction logic to ensure form data handlers can safely filter email addresses before persisting error state.
Updated the assertions in src/lib/logging/logger.test.ts to confirm that valid audit emails are now retained without compromising credential redaction behaviors.
Why it was done To resolve an over-redaction bug where audit logs were stripping the actor's email (a critical identifier for security investigations), while still maintaining strict PII redaction for user-submitted form state and error payloads.

How it was verified Manually analyzed form payloads and executed npx vitest run src/lib/logging/logger.test.ts which verified that standard credential strings and objects are appropriately masked, while basic logging contexts (like actor emails) pass unredacted.

✅ Required line:
Closes #781

[drips-wave]

@AbuJulaybeeb Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[RUKAYAT-CODER]

Thank you for contributing to the project