- Add permissions.go with permission definitions and checks
- Define permissions for all 21 S3 Tables operations
- Add permission checking helper functions
- Add getPrincipalFromRequest to extract caller identity
- Implement access control in CreateTableBucket, GetTableBucket, DeleteTableBucket
- Return 403 Forbidden for unauthorized operations
- Only bucket owner can perform operations (extensible for future policies)
- Add AuthError type for authorization failures
- Reduce handler.go from 370 to 195 lines (47% reduction)
- Remove duplicate ARN parsing and path helper functions
- Remove filer operation methods moved to filer_ops.go
- Remove metadata structure definitions moved to utils.go
- Keep handler focused on request routing and response formatting
- Maintains all functionality with improved code organization
