Fix #350: [Enhancement]: When some fields in UserProfile are NULL, th...

[JiwaniZakir]

Closes #350

Before

UserProfile.created_at and updated_at were typed as required string fields in dashboard/src/lib/api.ts. When the backend returned NULL for these fields, formatDate() in dashboard/src/routes/user-profile.tsx received undefined and passed it directly to new Date(), producing "Invalid Date" in some cells while other parts of the dashboard rendered nothing — causing visible inconsistency across the UI.

After

created_at and updated_at are now typed as string | undefined (created_at?: string, updated_at?: string), accurately reflecting that these fields can be NULL. formatDate() now accepts string | undefined and returns the nullDisplay sentinel value early when the input is falsy, ensuring a consistent, intentional display for missing timestamps throughout the dashboard.

Changes

• dashboard/src/lib/api.ts — Marked created_at and updated_at as optional (?) in the UserProfile interface to match actual backend behavior.
• dashboard/src/routes/user-profile.tsx — Updated the formatDate signature from (dateString: string) to (dateString: string | undefined) and added an early-return guard (if (!dateString) return nullDisplay;) before the new Date() call.

Testing

1. Seed or locate a UserProfile record with NULL values for created_at and/or updated_at.
2. Open the dashboard and navigate to the User Profile page.
3. Verify the affected date cells display the consistent null placeholder (e.g., —) instead of "Invalid Date" or a blank.
4. Verify that profiles with valid timestamps continue to display correctly formatted dates via toLocaleString().

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This PR was created with AI assistance (Claude). The changes were reviewed by quality gates and a critic model before submission.

[Teingi]

LGTM