fix(salary): preserve Unicode company identity in lookups (#570)

* fix(salary): preserve Unicode company identity in lookups

* fix(salary): restore accent folding after Nordic spellings

Address MadsLorentzen review feedback on #570: keep Unicode identity normalization and restore ASCII-typed accented-name controls on the documented CLI path.

tests/test_salary_unicode_cli.py

@@ -0,0 +1,62 @@
+"""Company identity survives the documented salary-data-file -> CLI path."""
+import json
+import shutil
+import subprocess
+import sys
+import unittest
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+
+TOOL = Path(__file__).resolve().parent.parent / "salary_lookup.py"
+
+
+class UnicodeSalaryCLI(unittest.TestCase):
+    def setUp(self):
+        directory = TemporaryDirectory()
+        self.addCleanup(directory.cleanup)
+        self.root = Path(directory.name)
+        shutil.copyfile(TOOL, self.root / TOOL.name)
+        # Same layout as README_SALARY_TOOL.md's manual-data setup. Keep the
+        # fixture next to an isolated copy of the CLI, never a user's dataset.
+        names = [
+            "腾讯", "東京 AI", "北京 AI", "Acme Corp", "Café Étoile",
+            "Nestlé Danmark A/S", "Ørsted A/S", "Mærsk A/S", "Åland A/S",
+        ]
+        data = {"companies": [
+            {"company": name, "categories": {"all_employees": {"index": 105}}}
+            for name in names
+        ]}
+        (self.root / "salary_data.json").write_text(
+            json.dumps(data, ensure_ascii=False), encoding="utf-8"
+        )
+
+    def lookup(self, query):
+        result = subprocess.run(
+            [sys.executable, str(self.root / TOOL.name), query, "--json"],
+            capture_output=True, text=True, encoding="utf-8",
+        )
+        self.assertEqual(result.returncode, 0, result.stderr + result.stdout)
+        return [row["company"] for row in json.loads(result.stdout)]
+
+    def test_exact_non_latin_company_can_be_found(self):
+        self.assertEqual(self.lookup("腾讯"), ["腾讯"])
+
+    def test_mixed_script_companies_do_not_collapse_to_a_latin_fragment(self):
+        self.assertEqual(self.lookup("東京 AI")[0], "東京 AI")
+
+    def test_canonically_equivalent_spelling_finds_the_same_company(self):
+        self.assertEqual(self.lookup("Cafe\u0301 E\u0301toile"), ["Café Étoile"])
+
+    def test_ascii_control_still_matches(self):
+        self.assertEqual(self.lookup("acme"), ["Acme Corp"])
+
+    def test_ascii_query_finds_accented_company(self):
+        self.assertEqual(self.lookup("Nestle"), ["Nestlé Danmark A/S"])
+
+    def test_nordic_spelling_variants_survive_accent_folding(self):
+        for query, expected in [("Orsted", "Ørsted A/S"),
+                                ("Maersk", "Mærsk A/S"),
+                                ("Aaland", "Åland A/S")]:
+            with self.subTest(query=query):
+                self.assertEqual(self.lookup(query), [expected])