AI integration library for Elixir with unified multi-provider API.

Key accomplishments:
- Multi-provider support (OpenAI, Anthropic, OpenRouter)
- Tool calling with per-provider wire format handling
- Stateful Agent GenServer with conversation history
- Structured output with JSON schema validation
- Real-time SSE streaming via Finch
- Pipeline (sequential) and Team (parallel) orchestration
- TestProvider sandbox, telemetry, NimbleOptions validation
- Published to Hex as phoenix_ai ~> 0.1.0

38/38 requirements satisfied. 311 tests passing.

See .planning/MILESTONES.md for full details.