SPARC Phase 2: Complete browser-adapter architecture

- Design BrowserAdapter and BrowserStatement class structure
- Define VFS auto-selection logic (OPFS > IndexedDB > memory)
- Architect statement reuse pattern with reset()
- Design error handling and transaction rollback strategy
- Document helper methods for parameter binding and row extraction
- Plan testing strategy for browser environment
- Define integration patterns and migration path

Next: TDD implementation phase

Author: michaeloboyle