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

apps/ai-service/rag/text.py

@@ -0,0 +1,23 @@
+"""Vietnamese text normalisation shared by drug and section resolution.
+
+Lives here rather than in `routing.py` because `sections.py` needs it too, and
+importing it from `routing` made `service -> sections -> routing -> service` a
+cycle. It is a text utility with no knowledge of drugs or sections.
+"""
+from __future__ import annotations
+
+import re
+import unicodedata
+
+WORD_RE = re.compile(r"\w+", re.UNICODE)
+
+
+def normalize_name(text: str) -> str:
+    """Casefold, strip diacritics, collapse to space-separated word tokens.
+
+    `đ` is replaced before decomposition because it is a distinct letter rather
+    than a base letter plus a combining mark, so NFKD leaves it intact.
+    """
+    decomposed = unicodedata.normalize("NFKD", text.casefold()).replace("đ", "d")
+    without_marks = "".join(char for char in decomposed if not unicodedata.combining(char))
+    return " ".join(WORD_RE.findall(without_marks))