test: clean up the paid eval lane (B1-B4, B6, B7)

- B1: delete paid files that assert nothing or cannot pass meaningfully:
  skill-llm-eval-spec and skill-e2e-spec-execute (test.todo), gemini-e2e
  (+ gemini-session-runner; no gemini CLI in CI), ship-idempotency (red
  since v1.63), the two opus-4-7 *-sonnet overlay wrappers, conductor-prose
  (+ its source-evaluation replay), codex-e2e-plan-format; drop their keys,
  scripts and census rows.
- B2: skill-llm-eval grades browse/sections/command-list.md with one union
  judge that also carries the baseline score pin; regression-vs-baseline
  deleted (paid run: pass, c4/c4/a4).
- B3: memory-pipeline, ios-qa, ios-qa-swift-build and plan-tune-cathedral
  make no model calls; renamed out of the paid glob so they run on every
  PR. Swift builds need GSTACK_TEST_SWIFT=1; device stub deleted.
- B4: codex-e2e*, outside-voice, aside and ios-device cannot run in the CI
  image; excluded from the weekly lane with a tracked re-entry condition.
- B6: fold opus-47's negative routing controls into skill-routing-e2e
  journey-negatives (paid run: 3/3 unrouted) and delete the file.
- B7: delete the never-green brain-privacy-gate eval; a free
  gstack-skill-start test now proves consent precedes artifacts egress.

test/overlay-measurement.test.ts

@@ -226,11 +226,11 @@ describe('literal fixture task correctness', () => {
     expect(() => assertReadOnlyWorkspace(before, snapshotWorkspace(dir))).toThrow('b');
   }));
   test('registry retires absent-nudge fanout cases and preserves remaining model/trial budgets', () => {
-    expect(OVERLAY_FIXTURES).toHaveLength(6);
+    expect(OVERLAY_FIXTURES).toHaveLength(4);
     expect(OVERLAY_FIXTURES.some((f) => f.id.includes('fanout') || f.comparison?.unsupportedHypothesis)).toBe(false);
     expect(OVERLAY_FIXTURES.every((f) => f.trials === 10 && f.comparison)).toBe(true);
     expect(OVERLAY_FIXTURES.filter((f) => f.model === 'claude-opus-4-7')).toHaveLength(3);
-    expect(OVERLAY_FIXTURES.filter((f) => f.model === 'claude-sonnet-4-6')).toHaveLength(3);
+    expect(OVERLAY_FIXTURES.filter((f) => f.model === 'claude-sonnet-4-6')).toHaveLength(1);
   });
 });