feat(runtime): implement single-article consolidation runtime and modularize codebase

tests/runtime/contract/test_candidates_payload_contract.py

@@ -0,0 +1,26 @@
+"""Contract tests for candidates-payload.schema.json."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import jsonschema
+
+from src.runtime.candidate.parser import build_candidates_payload
+from src.runtime.core.config import create_schema_registry, load_schema
+
+
+def test_candidates_payload_against_reference_articles():
+    schema = load_schema("candidates-payload.schema.json")
+    registry = create_schema_registry()
+    validator = jsonschema.Draft202012Validator(schema, registry=registry)
+
+    ref_dir = Path("evals/reference_20")
+    for art_file in ref_dir.glob("article_*.json"):
+        article_data = json.loads(art_file.read_text(encoding="utf-8"))
+        payload = build_candidates_payload(article_data)
+        errors = list(validator.iter_errors(payload))
+        assert len(errors) == 0, (
+            f"Payload for {art_file.name} failed schema: {[e.message for e in errors]}"
+        )