-- Add file upload metadata fields to captain_documents for PDF support
ALTER TABLE captain_documents ADD COLUMN IF NOT EXISTS file_size BIGINT DEFAULT 0;
ALTER TABLE captain_documents ADD COLUMN IF NOT EXISTS content_type VARCHAR(100) DEFAULT '';
ALTER TABLE captain_documents ADD COLUMN IF NOT EXISTS file_url VARCHAR(2048) DEFAULT '';

-- Allow external_link to be nullable (for direct content input documents)
ALTER TABLE captain_documents ALTER COLUMN external_link DROP NOT NULL;