refactor: bare structure for new backend architecture and runtime; no behavior changes yet

server/src/app.ts

@@ -0,0 +1,19 @@
+import { pathToFileURL } from 'url';
+
+import { getRuntimePaths } from './config/runtime.js';
+import type { ServerApplication } from './shared/types/app.js';
+import { logger } from './shared/utils/logger.js';
+
+export function createServerApplication(): ServerApplication {
+  const runtimePaths = getRuntimePaths();
+
+  return {
+    runtimePaths,
+    start: async () => {
+      logger.info('Bootstrapping backend via legacy runtime bridge', {
+        legacyRuntime: runtimePaths.legacyRuntimePath,
+      });
+      await import(pathToFileURL(runtimePaths.legacyRuntimePath).href);
+    },
+  };
+}