feat: Implement provider fallback system with comprehensive documentation and examples

- Added `PROVIDER-FALLBACK-SUMMARY.md` detailing the provider fallback implementation, including strategies, features, and validation results.
- Created core implementation files: `provider-manager.ts` and `long-running-agent.ts` with intelligent provider selection and fallback mechanisms.
- Developed example usage in `use-provider-fallback.ts` and validation tests in `test-provider-fallback.ts`.
- Documented key features such as automatic provider fallback, circuit breaker pattern, intelligent provider selection, real-time health monitoring, cost tracking, and checkpointing system.

feat: Finalize QUIC protocol integration with performance validation

- Added `QUIC_FINAL_STATUS.md` summarizing the QUIC implementation status, achievements, and pending tasks.
- Documented performance targets and technical achievements, including native Rust implementation and TypeScript integration.
- Updated `README_QUIC_PHASE1.md` to reflect the completion of Phase 1 and next steps for Phase 2.

docs: Enhance AgentDB CLI testing guide with comprehensive command examples

- Created `AGENTDB_TESTING.md` to provide a local testing guide for the AgentDB CLI, including quick start options and command categories.
- Included detailed examples for reflexion memory, skill library, causal memory graph, and more.

feat: Add simple command wrapper for Claude CLI

- Introduced `claude` script to facilitate running the Claude command via npx, handling process management and signal forwarding.

Author: ruvnet