Fix weather module DI (MeshService export + value import) and pass WEATHER_CRON through compose (#25)

src/weather/di.spec.ts

@@ -0,0 +1,17 @@
+import { Test } from '@nestjs/testing';
+import { describe, expect, it } from 'vitest';
+import { MeshService } from '../mesh/mesh.service.js';
+import { WeatherModule } from './weather.module.js';
+import { WeatherService } from './weather.service.js';
+
+describe('DI wiring (module graph)', () => {
+  // compile() instantiates providers but does not run lifecycle hooks, so no TCP connection is opened.
+  it('resolves WeatherService with MeshService provided by MeshModule', async () => {
+    process.env.MESH_DB_PATH = ':memory:'; // keep openMessageDb from touching the repo's ./data
+    const moduleRef = await Test.createTestingModule({
+      imports: [WeatherModule],
+    }).compile();
+    expect(moduleRef.get(WeatherService)).toBeInstanceOf(WeatherService);
+    expect(moduleRef.get(MeshService)).toBeInstanceOf(MeshService);
+  });
+});