Provides a storage abstraction through `IStorageProvider` interface and `StorageFactory` that selects between Dexie (IndexedDB), LocalStorage, Memory, and File implementations based on environment. Each implementation supports atomic updates, batch operations, import/export, and key-level locking. This pattern is cleanly isolated: another project could extract it to add offline persistence with pluggable backends. Demonstrates non-obvious skill in handling browser vs Node vs Electron storage differences with fallback strategies and startup safety checks.

A VCR (Video Cassette Recorder) test utility that records LLM API responses to JSON fixtures during `record` mode and replays them during `replay` mode, enabling deterministic, fast, and offline-compatible integration tests. It integrates with Playwright and Vitest, providing helpers like `waitForConditionOrVCRFailure` and `throwIfCurrentTestHasVCRFailure` to avoid cascading failures when fixtures drift. This is a self-contained, extractable asset: any project testing LLM-based features could adopt this pattern to reduce flakiness and API costs.

A Vue 3 composable that implements intelligent auto-scroll behavior for streaming output containers. It detects when the user manually scrolls away (via scroll direction/position heuristics) and pauses auto-scroll, resuming only when the user scrolls back to the bottom. It also handles edge cases like window resize and content overflow. The composable is fully isolated (no internal imports), depends only on Vue's `ref` and `onMounted`/`onUnmounted`, and can be dropped into any streaming UI component with minimal adaptation. Demonstrates user-experience craftsmanship beyond simple `scrollTop = scrollHeight`.