Issue #2: Implement Row Level Security (RLS) in Supabase

[MehulPardeshi]

Description:
Implement Row Level Security in Supabase to ensure data access control at the database level.

Tasks:

• Define access policies for each table
• Implement RLS for contributors table
• Implement RLS for moderation logs
• Add role-based policies
• Test security policies
• Document RLS implementation

Technical Requirements:

• Supabase RLS policies for each table
• Role-based access control
• Authentication integration

Acceptance Criteria:

• All tables have appropriate RLS policies
• Users can only access data they're authorized to see
• Admin roles have appropriate elevated access
• Security tests pass
• Documentation is complete