fix: add SPA fallback for client-side routing

NestJS was returning 404 JSON for SPA routes like /dashboard/search
because ServeStaticModule couldn't find a matching file and the request
fell through to NestJS router. Add explicit catch-all GET handler after
app.init() to serve index.html for non-API routes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/main.ts

@@ -3,12 +3,14 @@ import "./telemetry/tracing"; // MUST be first — instruments modules before th
 import { NestFactory } from "@nestjs/core";
 import { ConfigService } from "@nestjs/config";
 import helmet from "helmet";
+import { join } from "path";
 import type { Request, Response, NextFunction } from "express";
+import type { NestExpressApplication } from "@nestjs/platform-express";
 import { AppModule } from "./app.module";
 import { fileUploadValidation } from "./common/middleware/file-upload-validation.middleware";
 
 async function bootstrap() {
-  const app = await NestFactory.create(AppModule);
+  const app = await NestFactory.create<NestExpressApplication>(AppModule);
 
   const configService = app.get(ConfigService);
   const port = configService.get<number>("port", 4000);
@@ -52,6 +54,18 @@ async function bootstrap() {
     next();
   });
 
+  await app.init();
+
+  // SPA fallback: serve index.html for non-API GET requests
+  const webDistPath = join(__dirname, "..", "..", "web", "dist");
+  const expressApp = app.getHttpAdapter().getInstance();
+  expressApp.get("*", (req: Request, res: Response, next: NextFunction) => {
+    if (req.path.startsWith("/api")) {
+      return next();
+    }
+    res.sendFile(join(webDistPath, "index.html"));
+  });
+
   await app.listen(port);
   console.log(`API running on http://localhost:${port}`);
 }