verbose live UI + tool-level SSE events + Groq default + regression tests

api/datasets/__init__.py

@@ -0,0 +1,40 @@
+"""Dataset registry — the only dataset-specific surface in api/.
+
+Each subdirectory is one dataset. The folder name doubles as the Postgres
+schema name, the SQLite filename under `ctrl/seed/data/<name>.sqlite`, and
+the value of the `NVI_DATASET` env var that selects it.
+
+Inside each dataset folder:
+  schema_docs.yaml   — human descriptions for tables/columns
+  metrics.yaml       — canonical SQL fragments for business terms
+
+Both files are consumed by `api.tools.schema.load_schema()`. The Plan,
+Analyses, Tools, and Runtime code reference no dataset name — they read
+the active dataset through `settings.dataset`.
+"""
+
+from __future__ import annotations
+
+from functools import lru_cache
+from pathlib import Path
+from typing import Any
+
+import yaml
+
+from api.config import get_settings
+
+DATASETS_DIR = Path(__file__).resolve().parent
+
+
+def active_dir() -> Path:
+    return DATASETS_DIR / get_settings().dataset
+
+
+def available() -> list[str]:
+    return sorted(p.name for p in DATASETS_DIR.iterdir() if p.is_dir() and not p.name.startswith("_"))
+
+
+@lru_cache(maxsize=None)
+def read_yaml(dataset: str, filename: str) -> dict[str, Any]:
+    """Load one YAML file from a dataset folder. Cached per (dataset, file)."""
+    return yaml.safe_load((DATASETS_DIR / dataset / filename).read_text()) or {}