test(container): convert loadSettings + api/pad to TypeScript ESM

vitest's include glob is .ts-only (tests/container/specs/**/*.ts), so the
two .js files in tests/container were silently never collected, and the
docker workflow's `pnpm run test-container` step exited 1 with:

  No test files found, exiting with code 1

Both files were small and pure CJS (require() + exports). Converted to
ESM with vitest imports and import.meta.url-derived __dirname. Original
.js files removed.

Note: loadSettings reads ../../../settings.json.docker (three segments
up to repo root) — preserved the original path.

src/tests/container/loadSettings.ts

@@ -12,10 +12,15 @@
  *          back to a default)
  */
 
-const fs = require('fs');
-const jsonminify = require('jsonminify');
+import fs from 'fs';
+import jsonminify from 'jsonminify';
+import { fileURLToPath } from 'node:url';
+import { dirname } from 'node:path';
 
-function loadSettings() {
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+export function loadSettings(): any {
   let settingsStr = fs.readFileSync(`${__dirname}/../../../settings.json.docker`).toString();
   // try to parse the settings
   try {
@@ -33,5 +38,3 @@ function loadSettings() {
     console.error('whoops something is bad with settings');
   }
 }
-
-exports.loadSettings = loadSettings;

src/tests/container/specs/api/pad.ts

@@ -5,9 +5,11 @@
  * TODO: unify those two files, and merge in a single one.
  */
 
-const settings = require('../../loadSettings').loadSettings();
-const supertest = require('supertest');
+import { describe, it } from 'vitest';
+import supertest from 'supertest';
+import { loadSettings } from '../../loadSettings.js';
 
+const settings = loadSettings();
 const api = supertest(`http://${settings.ip}:${settings.port}`);
 const apiVersion = 1;