test: derive paid touchfiles from each eval's static closure (E)

touchfiles.test.ts now checks, per key, that the paid file's static
test/helpers and test/fixtures closure (plus fixture paths it names in string
literals) is covered, and names the file, path, chain and key to fix when it is
not. Free *.test.ts files are no longer touchfiles, so editing a free replay
test stops selecting paid evals: 950 entries removed, 653 real closure paths
added. The hand-copied inventories go: periodic-fixture-selection,
fake-impeccable-touchfiles and 45 per-file selection examples. Selection for
the sample edits (plan-eng-review template, claude-pty-runner,
plan-count-fixture, gstack-config) loses no case under either profile.
CONTRIBUTING documents the rule and its lower bound.

test/devex-peer-comparison-calibration.test.ts

@@ -27,8 +27,7 @@ test('DX artifact calibrations keep four acknowledged choices and vary only comp
 
 test('the separate DX calibration has a canonical periodic selector and all direct fixture inputs', () => {
   expect(E2E_TIERS[ID]).toBe('periodic');
-  for (const file of [`test/skill-e2e-${ID}.test.ts`, 'test/fixtures/devex-peer-comparison-classification.ts',
-    'test/devex-peer-comparison-calibration.test.ts']) {
+  for (const file of [`test/skill-e2e-${ID}.test.ts`, 'test/fixtures/devex-peer-comparison-classification.ts']) {
     expect(fs.existsSync(path.join(ROOT, file))).toBe(true);
     expect(selectTests([file], E2E_TOUCHFILES, []).selected).toEqual([ID]);
   }