feat(normalizer): alias index with maiden/married/nickname resolution

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tools/import-normalizer/persons.py

@@ -1,4 +1,5 @@
 """Person register parsing, name splitting, alias resolution."""
+import difflib
 import re
 import unicodedata
 from collections import Counter
@@ -141,3 +142,56 @@ def split_receivers(raw: str) -> list[str]:
         result.append(last_seg)
         return result
     return parts
+
+
+def _norm(name: str) -> str:
+    return re.sub(r"\s+", " ", _strip_accents(name).lower().replace(".", " ")).strip()
+
+
+class AliasIndex:
+    def __init__(self, people: list[Person]):
+        self._by_alias: dict[str, str] = {}
+        self._display: dict[str, str] = {}
+        self.known_ids: set[str] = {p.person_id for p in people}
+        first_name_ids: dict[str, list] = {}
+        for p in people:
+            self._display[p.person_id] = f"{p.first_name} {p.last_name}".strip()
+            # Ordered, de-duplicated forms (NOT a set) so alias order is deterministic — NFR-IDEM-01.
+            forms = [f"{p.first_name} {p.last_name}".strip()]
+            if p.maiden_name:
+                forms.append(f"{p.first_name} {p.maiden_name}".strip())
+            for extra in p.extra_given_names:
+                forms.append(f"{extra} {p.last_name}".strip())
+            if p.nickname:
+                forms.append(p.nickname)
+            seen = set()
+            for form in forms:
+                if form in seen:
+                    continue
+                seen.add(form)
+                key = _norm(form)
+                if key and key not in self._by_alias:
+                    self._by_alias[key] = p.person_id
+                    p.aliases.append(form)
+            if p.first_name:
+                ids = first_name_ids.setdefault(_norm(p.first_name), [])
+                if p.person_id not in ids:
+                    ids.append(p.person_id)
+        # first-name-only alias, only when unambiguous
+        for fname, ids in first_name_ids.items():
+            if len(ids) == 1 and fname not in self._by_alias:
+                self._by_alias[fname] = ids[0]
+
+    def resolve(self, name: str):
+        return self._by_alias.get(_norm(name))
+
+    def display(self, person_id: str) -> str:
+        return self._display.get(person_id, "")
+
+    def suggest(self, name: str):
+        keys = list(self._by_alias.keys())
+        match = difflib.get_close_matches(_norm(name), keys, n=1, cutoff=config.FUZZY_SUGGEST_THRESHOLD)
+        if not match:
+            return None, 0.0
+        score = difflib.SequenceMatcher(None, _norm(name), match[0]).ratio()
+        return self._by_alias[match[0]], score