feat: Session 12 AI Agents & NL->SQL
- src/barabadb/ai/llm.nim: LLM client for NL->SQL generation
- Supports OpenAI-compatible and Ollama APIs
- Configurable via BARADB_LLM_ENDPOINT, BARADB_LLM_MODEL, BARADB_LLM_API_KEY
- extractSQL() parses SQL from LLM responses (handles markdown blocks)
- Temperature 0.1 for deterministic SQL generation
- nl_to_sql() SQL function: natural language -> SQL
- Schema-aware prompt with table column definitions + indexes + RLS
- Query validation layer: wraps generated SQL in LIMIT 0 subquery
- Self-correction loop: on error, feeds error back to LLM for fix
- Tenant-aware: respects current session variables
- schema_prompt() SQL function: generates DDL + sample data + indexes
- Returns full CREATE TABLE statement with column types and constraints
- Includes up to 5 sample rows for context
- Lists indexes, RLS policies, foreign keys
- Perfect for feeding into LLM context
- All 340+ existing tests pass
dimgigov
e23b1d61d2