v1.91.8.0 test: smaller suite, derived paid selection, retired never-green evals

Release metadata for the test-reduction branch: VERSION 1.91.8.0 (1.91.7.0 is
claimed by #2983), CHANGELOG with the measured before/after table and a
contributor section, durations re-recorded on Ubicloud standard-16 (857 files,
0 failures), the agents digest, CONTRIBUTING's after-measurement row, the B8
fallback TODOS entry, and the after metrics, kept-vs-plan notes, B8 run and
census estimate in docs/test-audit-2026-09.md.

docs/TEST_PORTFOLIO.md

@@ -141,12 +141,14 @@ test/plan-count-design-ui-recovery.test.ts
 test/plan-count-native-input.test.ts
 test/plan-count-empty-review.test.ts
 test/plan-count-owned-permission.test.ts
-test/plan-count-quoted-frame-ak.test.ts
+test/plan-count-file-permission.test.ts
 test/plan-count-truncated-question.test.ts
 test/plan-count-preview-footer.test.ts
 test/eng-test-plan-edit-approval.test.ts
 ```
 
+The quoted-frame selector was folded into `test/plan-count-file-permission.test.ts` in the 2026-09 audit.
+
 The publication/watchdog pair is `test/autoplan-publication-guard.test.ts` and
 `test/cso-watchdog.test.ts`. The live pair is
 `test/skill-e2e-auq-consistency.test.ts` and