feat(ai-core): add LLM orchestration engine
- model: shared data types (Message, Intent, StreamToken, LLMMessage)
- persona: YAML/Raw loading + system prompt injection
- llm: OpenAI-compatible adapter with streaming + semantic cache
- context: sliding window context store with token budgeting
- subsession: parallel provider dispatch + review message parser
- orchestrator: intent analysis pipeline (IoT/greeting/chat/memory)
- background: autonomous thinking engine
- 20+ tests, build + vet clean, ~130 total tests
Aska
3b3e5a0697