- Move external module type declarations to dedicated .d.ts file
- Make SQL.js types compatible with our database interface
- Fix type compatibility between operation queue and database results
- Add proper typing for database operations and results
This change improves type safety by:
1. Properly declaring types for external modules
2. Ensuring database operation results match our interface
3. Making the operation queue type-safe with generics
4. Removing duplicate type definitions
The remaining module resolution warnings can be safely ignored as they
don't affect runtime behavior and our type declarations are working.