Client-side: validates ALL mandatory DB fields before allowing next/submit
- Step 1: name, phone, gender, date_of_birth (or NID)
- Step 2: form_date, join_date
- Step 3: membership_value
- Step 5: each spouse needs name, DOB/NID, marriage_date, join_date
         each child needs name, DOB/NID, join_date
         each temp member needs name, DOB/NID, category
- Red border + Arabic error on each missing field, scrolls to first error

Server-side: full validation before any DB write
- Rejects with clear Arabic messages listing every missing field
- No more placeholder dates or fake phone numbers
- If anything bypasses JS, server still blocks with human-readable errors
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>