fix(import): NFKD normalization for non-Romanian diacritics

clean_web_text used a hard-coded Romanian-only translation map, so Hungarian
(BALÁZS LORÁNT), German, Czech, Polish names passed through unchanged into
SQLite and Oracle ROA. Replace with unicodedata.normalize('NFKD') + combining
mark strip — covers RO/HU/DE/CZ/PL/FR/ES universally. Romanian cedilla legacy
forms (ş/ţ/Ş/Ţ) remain handled (NFKD decomposes to base + combining cedilla).
Stroke letters not decomposed by NFKD (ß, ł, đ, ø, æ, œ) covered via
_NFKD_OVERRIDES translation map.

sync_service._addr_match.norm migrated off the removed _DIACRITICS constant
to clean_web_text; address matching now also handles non-RO diacritics.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/tests/test_business_rules.py

@@ -821,6 +821,49 @@ class TestFormatAddressForOracle:
         assert result == "JUD:Bacau;Zemes;Str Principala Modarzau Blocuri"
 
 
+class TestCleanWebTextDiacritics:
+    """clean_web_text strips diacritics across RO/HU/DE/CZ/PL via NFKD."""
+
+    def test_hungarian_acute(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("BALÁZS LORÁNT") == "BALAZS LORANT"
+
+    def test_hungarian_double_acute(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("Lőrincz Ödön") == "Lorincz Odon"
+        assert clean_web_text("Erdős Pál") == "Erdos Pal"
+
+    def test_romanian_comma_below_modern(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("Ștefan Țîrcă") == "Stefan Tirca"
+        assert clean_web_text("ȘTEFAN ȚÎRCĂ") == "STEFAN TIRCA"
+
+    def test_romanian_cedilla_legacy_preserved(self):
+        """Cedilla ş/ţ/Ş/Ţ must still normalize to s/t/S/T (regression guard)."""
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("şcoala") == "scoala"
+        assert clean_web_text("ţara") == "tara"
+        assert clean_web_text("ŞTEFAN ŢARA") == "STEFAN TARA"
+        assert clean_web_text("IAŞI") == "IASI"
+
+    def test_german_umlaut_and_eszett(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("Müller Straße") == "Muller Strasse"
+
+    def test_czech_polish(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("Dvořák") == "Dvorak"
+        assert clean_web_text("Łódź") == "Lodz"
+
+    def test_html_entity_unescape(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("Café") == "Cafe"
+
+    def test_empty_input(self):
+        from app.services.import_service import clean_web_text
+        assert clean_web_text("") == ""
+
+
 # ===========================================================================
 # Group 11: TestRefreshOrderAddress
 # ===========================================================================