fix(convert-salary-excel): reject ambiguous dot thousands separators (#326)

CHANGELOG.md

@@ -11,6 +11,20 @@ prefer updating to a tagged release over pulling raw `master` (see
 files a release touched; `python3 tools/check_upstream_updates.py` lists them with
 per-file diff commands.
 
+## [Unreleased]
+
+### Fixed
+
+- **`convert_salary_excel.py` no longer misreads whole-thousands cells from a Danish-locale
+  export** - a cell like `60.000` (thousands separator, no decimal comma) was handed to
+  `float()` and silently written as `60.0`, a 1000x-wrong salary in `salary_data.json` that
+  then rendered with a meaningless `vs baseline` percentage in `/apply`. The comma-side
+  mirror (`1,234`) was already guarded as ambiguous and skipped; the dot side had no guard,
+  and tests only pinned the both-separators form (`1.234,5`). `\d+\.\d{3}` is now rejected
+  the same way, so the shared never-guess policy applies to both separators and the rows in
+  between (e.g. `60.000,50`, `108,5`) keep parsing exactly as before. Pinned by
+  `tests/test_convert_salary_excel.py`.
+
 ## [1.5.0] - 2026-08-12
 
 ### Added

tests/test_convert_salary_excel.py

@@ -230,6 +230,21 @@ class DetectColumnTypeTests(unittest.TestCase):
 
         self.assertEqual(companies[0]["categories"], {})
 
+    def test_parse_sheet_skips_ambiguous_single_dot_thousands_string(self):
+        # "1.234" is the dot-side mirror of the comma guard above: in a
+        # decimal-dot locale it is 1.234, while a Danish export (whole
+        # thousands, no decimal comma, e.g. "60.000") means 1234/60000.
+        # float() used to write the 1000x-smaller value silently - the
+        # same never-guess policy must apply to both separators.
+        ws = FakeWorksheet([
+            ("Company", "Salary Index"),
+            ("Example Corp", "1.234"),
+        ])
+
+        companies = parse_sheet(ws)
+
+        self.assertEqual(companies[0]["categories"], {})
+
     def test_parse_sheet_pairs_interleaved_count_index_columns_by_name(self):
         ws = FakeWorksheet([
             ("Company", "Antal kvinder", "Antal mænd", "Kvinder indeks", "Mænd indeks"),

tools/convert_salary_excel.py

@@ -70,6 +70,9 @@ def parse_numeric_cell(value):
         if re.fullmatch(r"[+-]?\d+,\d{3}", text):
             raise ValueError("ambiguous comma separator")
         text = text.replace(",", ".")
+    elif "." in text:
+        if re.fullmatch(r"[+-]?\d+\.\d{3}", text):
+            raise ValueError("ambiguous dot separator")
     return float(text)