- Fix type assertion panics in library.go (lines 58, 109, 237)
Changed from *database.Users to database.Users to match JWT middleware
- Fix ISBN type mismatch in ebook.go (lines 249, 308)
Changed from pgtype.Text to string to match database schema
- Fix ISBN type mismatch in ebook_scanner.go (line 421)
Changed from pgtype.Text to string to match database schema
These changes fix 500 errors in library creation and ebook operations.