Wire the guarded conversational RAG answer layer end-to-end

apps/ai-service/tests/test_section_order.py

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+"""A section must be served in the order it was written.
+
+Found 2026-08-05 by reading a real answer in the UI rather than a test:
+`liều dùng paracetamol` opened mid-sentence on `5 - 12 tuổi:` and buried
+`Liều lượng: Người lớn:` seven hundred words down. Qdrant scrolls in point-id
+order and point ids are `uuid5(chunk_id)`, so PARACETAMOL's five dosing parts
+came back **3, 4, 1, 2, 0**.
+
+This is a clinical defect, not a cosmetic one: a reader who stops partway
+through stops in the middle of a different population's dose.
+"""
+from __future__ import annotations
+
+from adapters.qdrant import QdrantRetriever
+
+
+class _ScrambledClient:
+    """Returns parts out of order, the way a real scroll did."""
+
+    def __init__(self, part_indices: list[int], include_index: bool = True) -> None:
+        self._payloads = [
+            {
+                "chunk_id": f"paracetamol__lieu__{index}",
+                "drug_id": "paracetamol",
+                "section_key": "lieu_luong_va_cach_dung",
+                "chunk_kind": "prose",
+                "text": f"part {index}",
+                "source_refs": [{"physical_page": 1120, "precision": "page"}],
+                **({"part_index": index} if include_index else {}),
+            }
+            for index in part_indices
+        ]
+
+    def scroll(self, **kwargs):
+        points = [type("P", (), {"payload": payload})() for payload in self._payloads]
+        return points, None
+
+
+class _Embedder:
+    dimensions = 4
+
+    def embed_query(self, text: str) -> list[float]:  # never used by this route
+        raise AssertionError("find_by_section must not embed anything")
+
+
+def _hits(part_indices: list[int], include_index: bool = True) -> list[str]:
+    retriever = QdrantRetriever(
+        _ScrambledClient(part_indices, include_index), "duocthu_v1", _Embedder()
+    )
+    return [
+        hit.document.text
+        for hit in retriever.find_by_section("paracetamol", "lieu_luong_va_cach_dung")
+    ]
+
+
+def test_the_exact_scramble_observed_against_the_real_collection():
+    assert _hits([3, 4, 1, 2, 0]) == [
+        "part 0",
+        "part 1",
+        "part 2",
+        "part 3",
+        "part 4",
+    ]
+
+
+def test_an_already_ordered_section_is_left_alone():
+    assert _hits([0, 1, 2, 3]) == ["part 0", "part 1", "part 2", "part 3"]
+
+
+def test_a_part_missing_its_index_is_kept_and_sorted_last():
+    """Dropping it would silently shorten a dose list, which is the one
+    outcome worse than showing it out of order."""
+    texts = _hits([1, 0], include_index=False)
+
+    assert len(texts) == 2
+    assert set(texts) == {"part 0", "part 1"}