feat(settings): add SettingsService with cache and emitter\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/lib/__tests__/settings.server.test.ts

@@ -0,0 +1,12 @@
+// app/lib/__tests__/settings.server.test.ts
+import { settingsService } from '../settings.server';
+
+describe('SettingsService', () => {
+  test('set and get', async () => {
+    const key = `test_key_${Date.now()}`;
+    const val = { enabled: true };
+    await settingsService.set(key, val, 'test');
+    const got = await settingsService.get(key);
+    expect(got).toEqual(val);
+  });
+});

app/lib/settings.server.ts

@@ -0,0 +1,43 @@
+// app/lib/settings.server.ts
+import { PrismaClient } from '@prisma/client';
+import EventEmitter from 'events';
+
+const prisma = new PrismaClient();
+
+type JSONValue = any;
+
+class SettingsService extends EventEmitter {
+  private cache: Map<string, JSONValue> = new Map();
+  private initialized = false;
+
+  async init() {
+    if (this.initialized) return;
+    const rows = await prisma.appSetting.findMany();
+    rows.forEach(r => this.cache.set(r.key, r.value));
+    this.initialized = true;
+  }
+
+  async get(key: string) {
+    if (!this.initialized) await this.init();
+    return this.cache.has(key) ? this.cache.get(key) : null;
+  }
+
+  async set(key: string, value: JSONValue, updatedBy?: string) {
+    if (!this.initialized) await this.init();
+    await prisma.appSetting.upsert({
+      where: { key },
+      update: { value, updatedBy },
+      create: { key, value, updatedBy },
+    });
+    this.cache.set(key, value);
+    this.emit('update', { key, value });
+    return { key, value };
+  }
+
+  subscribe(fn: (payload: { key: string; value: any }) => void) {
+    this.on('update', fn);
+    return () => this.off('update', fn);
+  }
+}
+
+export const settingsService = new SettingsService();