docs(changelog): strip internal jargon from [Unreleased]

Removes WI-*, INV-*, and UAT BUG-* / UAT round NN references from the
v4.1.0-pending changelog, since these are internal tracker/session
artifacts that external readers cannot resolve. Public refs (ADR-NNNN,
audit-findings NNNN) preserved.

Also consolidates four cases of intra-release churn that don't make
sense in the changelog format:

- Schema versions: 8-step patch sequence collapses to one-liner
  (0.4.0 → 0.5.8). Within-release patch bumps are not relative to the
  prior release.
- Pattern shim: drop "shim is removed in next entry" from Wave 5;
  reword line 67 to describe Pattern.framework_role as a field rather
  than a shim-replacement. Net effect for the audience: the shim
  never existed.
- Regression guard: heading marked "(strict, CI-blocking)" in Added;
  "promotes from smoke check to strict assertion" tail dropped from
  Changed. The audience just sees "strict at release".
- Wave 6: 6 PR-by-PR sub-bullets reorganized as 3 sub-bullets by what
  changed (74 promotions / 15 FOLDs / DEPRECATE-NO-FOLDs +
  CANONICAL reclassifications). Same evidence preserved.

No code changes. Pure changelog editing.

Signed-off-by: jgstern-agent <josh-agent@iterabloom.com>

Author: jgstern-agent

.ci/affected-tests.txt

@@ -1,5 +1,5 @@
 # Test selection manifest
-# Generated by smart-test at 2026-05-07T22:20:17-04:00
+# Generated by smart-test at 2026-05-07T23:34:29-04:00
 # Mode: targeted
 # Baseline: 63feb37916959501e7e858532b7796ba46f3b0ad
 # Changed files: 217