fix(pii): remove real member names tied to payments

- Scrub three parity fixtures that still held raw bank messages
- Use fictional names in the junior regression test, its changelog
  entry and its plan file
- State the rule in CLAUDE.md: a real name as a bare test input is
  fine; a real name next to payment details, or any junior or parent
  name, is not
- Tick T4 in the cleanup task list

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

legacy/tests/test_match_members.py

@@ -51,21 +51,21 @@ class TestMatchMembersExact(unittest.TestCase):
     def test_shared_first_name_junior_in_roster_wins_exact(self):
         # Regression: two members share first name "Jáchym"; message has full name
         # of the junior-only member → exact match must win, no [?] on the adult.
-        roster = ["Jáchym Hrušák (G)", "Jáchym Kubík"]
+        roster = ["Jáchym Novotný (G)", "Jáchym Dvořák"]
         result = match_members(
-            "JIŘÍ KUBÍK Jáchym Kubík: 01/2026+03/2026+04/2026", roster
+            "JIŘÍ DVOŘÁK Jáchym Dvořák: 01/2026+03/2026+04/2026", roster
         )
-        self.assertEqual(result, [("Jáchym Kubík", "auto")])
+        self.assertEqual(result, [("Jáchym Dvořák", "auto")])
 
     def test_shared_first_name_without_junior_in_roster_falls_back(self):
-        # Without Kubík in the roster (old behaviour), Hrušák wins via first-name
+        # Without Dvořák in the roster (old behaviour), Novotný wins via first-name
         # partial match — confirms the roster-expansion fix is the real solution.
-        roster = ["Jáchym Hrušák (G)"]
+        roster = ["Jáchym Novotný (G)"]
         result = match_members(
-            "JIŘÍ KUBÍK Jáchym Kubík: 01/2026+03/2026+04/2026", roster
+            "JIŘÍ DVOŘÁK Jáchym Dvořák: 01/2026+03/2026+04/2026", roster
         )
         names = [r[0] for r in result]
-        self.assertIn("Jáchym Hrušák (G)", names)
+        self.assertIn("Jáchym Novotný (G)", names)
 
 
 if __name__ == "__main__":