test: delete test-infrastructure dead code (G)

- exit-propagation drives the runner's real strict verdict
  (BunTestOutputClassifier + strictTestExitCode); delete the unused
  shardRunLooksTruncated predicate.
- delete skill-coverage-matrix registry + its gate (nothing reads it; the
  floor already iterates skillCensus()).
- delete touchfiles-facade export-parity tests (Bun fails missing imports
  at link time) and the duplicated E2E_TIERS tier-value test.
- delete brain-cache-spec TRANSPORT_DEFAULT_POLICY, SKILL_RUN_RETENTION_DAYS
  and the now-unused BrainTrustPolicy type with their literal tests.
  AUTOPLAN_PREFLIGHT_BUDGET_BYTES stays: skill-preflight-budget enforces it
  against real resolver output.
- delete audit-compliance's JSDoc-comment grep.

test/exit-propagation.test.ts

@@ -3,7 +3,7 @@ import { spawnSync } from 'child_process';
 import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
-import { shardRunLooksTruncated } from '../scripts/test-free-shards';
+import { BunTestOutputClassifier, strictTestExitCode } from '../scripts/test-strict-output';
 
 // Fault-injection companion to test/no-suicide-exit.test.ts.
 //
@@ -11,9 +11,10 @@ import { shardRunLooksTruncated } from '../scripts/test-free-shards';
 // process.exit. This file proves, with real bun output, WHY that guard and
 // the sharded runner's summary check both exist: `bun test` itself exits 0
 // when a mid-suite process.exit(0) fires — the truncated run is
-// indistinguishable from a green one by exit code alone. The sharded
-// runner's shardRunLooksTruncated() predicate is the detection layer; these
-// tests drive it with genuine truncated and genuine complete runs.
+// indistinguishable from a green one by exit code alone. The runner's strict
+// verdict (BunTestOutputClassifier + strictTestExitCode, used by runFreeShard)
+// is the detection layer; these tests drive it with genuine truncated and
+// genuine complete runs.
 
 function runBunTest(dir: string) {
   return spawnSync('bun', ['test', '.'], {
@@ -24,6 +25,13 @@ function runBunTest(dir: string) {
   });
 }
 
+function strictVerdict(r: ReturnType<typeof runBunTest>, expectedFiles: number): number {
+  const classifier = new BunTestOutputClassifier();
+  classifier.write(r.stdout ?? '', 'stdout');
+  classifier.write(r.stderr ?? '', 'stderr');
+  return strictTestExitCode(r.status ?? 1, classifier.end(), expectedFiles);
+}
+
 function withFixtureDir(files: Record<string, string>, fn: (dir: string) => void) {
   const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'exit-prop-'));
   try {
@@ -46,16 +54,15 @@ const FAILING_FIXTURE = fs.readFileSync(path.join(FIXTURES, 'failing.txt'), 'utf
 const PASSING_FIXTURE = fs.readFileSync(path.join(FIXTURES, 'passing.txt'), 'utf8');
 
 describe('exit-code propagation (fault injection)', () => {
-  test('a mid-suite process.exit(0) yields exit 0 with NO summary — and the shard predicate catches it', () => {
+  test('a mid-suite process.exit(0) yields exit 0 with NO summary — and the strict verdict fails it', () => {
     withFixtureDir(
       { 'a-suicide.test.ts': SUICIDE_FIXTURE, 'b-failing.test.ts': FAILING_FIXTURE },
       (dir) => {
         const r = runBunTest(dir);
-        const combined = `${r.stdout ?? ''}${r.stderr ?? ''}`;
         if (r.status === 0) {
-          // The dangerous shape: green exit, truncated run. The predicate
-          // MUST flag it — this is the assertion that guards the suite.
-          expect(shardRunLooksTruncated(r.status, combined)).toBe(true);
+          // The dangerous shape: green exit, truncated run. The strict
+          // verdict MUST fail it — this is the assertion that guards the suite.
+          expect(strictVerdict(r, 2)).not.toBe(0);
         } else {
           // If a future bun version starts propagating the failure itself,
           // even better — nothing to detect. Either way, never green+silent.
@@ -68,18 +75,16 @@ describe('exit-code propagation (fault injection)', () => {
   test('a complete green run is NOT flagged as truncated', () => {
     withFixtureDir({ 'ok.test.ts': PASSING_FIXTURE }, (dir) => {
       const r = runBunTest(dir);
-      const combined = `${r.stdout ?? ''}${r.stderr ?? ''}`;
       expect(r.status).toBe(0);
-      expect(shardRunLooksTruncated(r.status, combined)).toBe(false);
+      expect(strictVerdict(r, 1)).toBe(0);
     });
   });
 
-  test('a plain failing run propagates nonzero and is not the silent case', () => {
+  test('a plain failing run propagates nonzero through the strict verdict', () => {
     withFixtureDir({ 'fail.test.ts': FAILING_FIXTURE }, (dir) => {
       const r = runBunTest(dir);
-      const combined = `${r.stdout ?? ''}${r.stderr ?? ''}`;
       expect(r.status).not.toBe(0);
-      expect(shardRunLooksTruncated(r.status, combined)).toBe(false);
+      expect(strictVerdict(r, 1)).not.toBe(0);
     });
   });
 });