Add sunrise Threads automation and improve capture and character interactions

tests/threads-config.test.ts

@@ -0,0 +1,16 @@
+import assert from 'node:assert/strict';
+import { test } from 'node:test';
+import { loadThreadsConfig } from '../server/threads/config.ts';
+
+test('Threads JSON sample loads with relative paths and no embedded token', () => {
+  const config = loadThreadsConfig(new URL('../.env.threads.sample.json', import.meta.url));
+  assert.equal(config.accessToken, '');
+  assert.equal(config.siteUrl, 'https://sunrise.horoli.kr');
+  assert.equal(config.imageDir, 'dist/threads-captures');
+});
+
+test('missing configuration is permitted only for capture preview', () => {
+  const missing = new URL('../.tmp/threads-config-does-not-exist.json', import.meta.url);
+  assert.throws(() => loadThreadsConfig(missing), /copy .env.threads.sample.json/);
+  assert.equal(loadThreadsConfig(missing, true).accessToken, '');
+});