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>

docs/plans/2026-10-08-1026-pre-feature-cleanup-tasks.md

@@ -58,7 +58,8 @@ before new feature work starts. Companion to the Go rewrite tracker,
     current year.
   - Same applies to the `sync-2026` Makefile target.
   - Moot if Python is retired before then.
-- [ ] **T4** Remove member names from tracked files (PII rule in `CLAUDE.md`).
+- [x] **T4** Remove member names from tracked files (PII rule in `CLAUDE.md`).
+  Done 2026-10-09 in a narrower form, see Notes & decisions. Original task:
   - `CHANGELOG.md` line 29 names a member in a fix description.
   - `tests/test_match_payments.py`, `tests/test_reconcile_exceptions.py` and
     `go/internal/domain/reconcile/reconcile_test.go` use names that may be
@@ -172,3 +173,16 @@ Plan: [2026-10-08-1103-api-parity-vs-months-to-show.md](2026-10-08-1103-api-pari
 ## Notes & decisions
 
 (Add entries as you go. Format: `YYYY-MM-DD — short note`.)
+
+- 2026-10-09 — T4 scope decided by the owner: a real name as a bare test
+  input is acceptable; a real name next to payment details, raw bank
+  messages, or any junior or parent name is not. Replaced the junior
+  regression-test names (test, changelog, plan) with fictional ones and
+  scrubbed three parity fixtures that still held raw bank messages. The
+  other test names stay. Git history was not rewritten. Rule recorded in
+  `CLAUDE.md`.
+- 2026-10-09 — The `real_*` parse_month_references seeds pick rows from the
+  live payments cache by index (`_REAL_PMR_INDICES`). The sheet has changed
+  since capture, so `make capture-fixtures` now rewrites those fixtures with
+  different messages. Commit only the fixtures a change needs, or replace
+  the index-based seeds with fixed synthetic ones.