fix: pre-existing test failure in skill-e2e-bws operational-learning

Root cause was the fixture, not model behavior: gstack-learnings-log gained
an import of lib/jsonl-store.ts in the v1.57.5.0 injection-sanitization wave,
but the test copies only bin/ scripts into its sandbox — the inline bun
import failed and the script exited 1 before writing, on every run, on main
too (reproduced at a5833c41). Fixture now stages lib/jsonl-store.ts beside
bin/; verified deterministically (script exits 0, learning written) and via
the paid test (1 pass).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/skill-e2e-bws.test.ts

@@ -192,13 +192,21 @@ Report the exact output — either "READY: <path>" or "NEEDS_SETUP".`,
     run('git', ['add', '.']);
     run('git', ['commit', '-m', 'initial']);
 
-    // Copy bin scripts
+    // Copy bin scripts + the lib module they import. gstack-learnings-log
+    // does `import ... from '$SCRIPT_DIR/../lib/jsonl-store.ts'` (v1.57.5.0
+    // injection sanitization) — without lib/ alongside bin/, the script exits
+    // 1 before writing anything, failing this test for a fixture reason, not
+    // a model-behavior reason (root-caused during the v1.58.0.0 ship; fails
+    // identically on main).
     const binDir = path.join(opDir, 'bin');
     fs.mkdirSync(binDir, { recursive: true });
     for (const script of ['gstack-learnings-log', 'gstack-slug']) {
       fs.copyFileSync(path.join(ROOT, 'bin', script), path.join(binDir, script));
       fs.chmodSync(path.join(binDir, script), 0o755);
     }
+    const libDir = path.join(opDir, 'lib');
+    fs.mkdirSync(libDir, { recursive: true });
+    fs.copyFileSync(path.join(ROOT, 'lib', 'jsonl-store.ts'), path.join(libDir, 'jsonl-store.ts'));
 
     // gstack-learnings-log will create the project dir automatically via gstack-slug