test(ui): give the whole-tree scratch-dir sweep bases it can read in three ui/ script tests

The slow tier of `pnpm check:pm-dispatch-gates` runs only on push and
schedule, and since the ui/ import it reads ui/ sources too. Two of its
live-tree cases went red on three ui/ test files:

- check-node-esm-load.test.ts binds `dir` to a temp directory in most
  tests and to `path.join(REPO_ROOT, 'packages/fields' | 'packages/auth')`
  in two. The sweep does not track scope and an in-tree reading wins, so
  every `mkdirSync(path.join(dir, ...))` read as a directory created in
  ui/packages/fields. The two package-reading tests now say `pkgDir`.
- markdown-test-inputs.test.ts and select-affected-tests-wiring.test.ts
  declared `let scratch = ''` and assigned the real temp base in
  beforeAll. The empty literal read as a cwd-relative mkdtempSync base.
  They now declare `let scratch: string;`, so the one assignment is the
  only reading.

No gate changes. Tests unchanged in behaviour (86/86).

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HssnEmZ59WGARsErPSbRpf

Author: claude

ui/scripts/__tests__/check-node-esm-load.test.ts

@@ -369,24 +369,24 @@ describe('the scope this gate ratchets, now that the emit question is answered',
     // sources — so nothing live left the leg with it. The sources keep a
     // STRICTER guard than this heuristic: that config pins `nodenext`, under
     // which a missing relative extension is TS2835 in the package's own build.
-    const dir = path.join(REPO_ROOT, 'packages/fields');
-    const build = JSON.parse(fs.readFileSync(path.join(dir, 'package.json'), 'utf8')).scripts.build;
+    const pkgDir = path.join(REPO_ROOT, 'packages/fields');
+    const build = JSON.parse(fs.readFileSync(path.join(pkgDir, 'package.json'), 'utf8')).scripts.build;
 
-    expect(effectiveNoEmit(path.join(dir, 'tsconfig.json'))).toBe(true);
-    expect(buildPreservesSpecifiers(build, dir)).toBe(false);
-    expect(parseTsconfig(path.join(dir, 'tsconfig.json')).compilerOptions?.noEmit).toBeUndefined();
+    expect(effectiveNoEmit(path.join(pkgDir, 'tsconfig.json'))).toBe(true);
+    expect(buildPreservesSpecifiers(build, pkgDir)).toBe(false);
+    expect(parseTsconfig(path.join(pkgDir, 'tsconfig.json')).compilerOptions?.noEmit).toBeUndefined();
   });
 
   it('keeps `@object-ui/auth` in the leg on its DECLARED noEmit, not on a catch', () => {
     // Its config throws under the old reader too, so it was in the leg by
     // accident. It declares `"noEmit": false` outright, so the verdict is
     // unchanged — what changes is that it is now a reading.
-    const dir = path.join(REPO_ROOT, 'packages/auth');
-    const build = JSON.parse(fs.readFileSync(path.join(dir, 'package.json'), 'utf8')).scripts.build;
+    const pkgDir = path.join(REPO_ROOT, 'packages/auth');
+    const build = JSON.parse(fs.readFileSync(path.join(pkgDir, 'package.json'), 'utf8')).scripts.build;
 
-    expect(parseTsconfig(path.join(dir, 'tsconfig.json')).compilerOptions?.noEmit).toBe(false);
-    expect(effectiveNoEmit(path.join(dir, 'tsconfig.json'))).toBe(false);
-    expect(buildPreservesSpecifiers(build, dir)).toBe(true);
+    expect(parseTsconfig(path.join(pkgDir, 'tsconfig.json')).compilerOptions?.noEmit).toBe(false);
+    expect(effectiveNoEmit(path.join(pkgDir, 'tsconfig.json'))).toBe(false);
+    expect(buildPreservesSpecifiers(build, pkgDir)).toBe(true);
   });
 });
 

ui/scripts/__tests__/markdown-test-inputs.test.ts

@@ -113,7 +113,7 @@ const [TYPE_CHECK_STEP, TEST_STEP, DIST_PINS_STEP, E2E_STEP] = STEPS;
 
 type Outcome = { shouldRun: string; log: string };
 
-let scratch = '';
+let scratch: string;
 
 function git(cwd: string, ...args: string[]): void {
   execFileSync('git', args, { cwd, stdio: 'pipe' });

ui/scripts/__tests__/select-affected-tests-wiring.test.ts

@@ -134,7 +134,7 @@ function parseOutputs(text: string): Record<string, string> {
   return outputs;
 }
 
-let scratch = '';
+let scratch: string;
 const nodeDir = path.dirname(process.execPath);
 
 /** Write an executable stand-in for `name` into a fresh bin directory. */