Add SmartFS core library with providers, builders, interfaces, docs, tests and CI
- Add core TypeScript sources and public exports: SmartFs, SmartFsFile, SmartFsDirectory, SmartFsTransaction, SmartFsWatcher and ts/index.ts
- Add two providers: SmartFsProviderNode (Node.js fs/promises + fs.watch) and SmartFsProviderMemory (in-memory implementation used for testing)
- Add provider and type contracts: ISmartFsProvider, IProviderCapabilities and comprehensive mod.types definitions
- Implement transactions with prepare/execute/rollback, atomic writes, Web Streams-based read/write streams, and file watching with debouncing and filters
- Add tests entry (test/test.ts) and test scaffolding for memory and node providers