fix: resolve exchange rate errors from silent failure, reference bug, and missing dataSource filter

Three fixes for exchange rate reliability with MANUAL data source:

1. app.controller.ts: Log error in catch block instead of swallowing.
   The empty catch {} hides exchange rate initialization failures.

2. exchange-rate-data.service.ts: Use spread copy instead of reference
   assignment for resultExtended, preventing mutation of the source
   object during reverse-rate computation.

3. manual.service.ts: Add dataSource filter to MarketData query so
   DISTINCT ON (symbol) returns the correct row for symbols with
   entries from multiple data providers.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/api/src/app/app.controller.ts

@@ -1,9 +1,11 @@
 import { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
 
-import { Controller } from '@nestjs/common';
+import { Controller, Logger } from '@nestjs/common';
 
 @Controller()
 export class AppController {
+  private readonly logger = new Logger(AppController.name);
+
   public constructor(
     private readonly exchangeRateDataService: ExchangeRateDataService
   ) {
@@ -13,6 +15,8 @@ export class AppController {
   private async initialize() {
     try {
       await this.exchangeRateDataService.initialize();
-    } catch {}
+    } catch (error) {
+      this.logger.error(error);
+    }
   }
 }

apps/api/src/services/data-provider/manual/manual.service.ts

@@ -161,7 +161,8 @@ export class ManualService implements DataProviderInterface {
         where: {
           symbol: {
             in: symbols
-          }
+          },
+          dataSource: this.getName()
         }
       });
 

apps/api/src/services/exchange-rate-data/exchange-rate-data.service.ts

@@ -203,7 +203,7 @@ export class ExchangeRateDataService {
       }
     }
 
-    const resultExtended = result;
+    const resultExtended = { ...result };
 
     for (const symbol of Object.keys(result)) {
       const [currency1, currency2] = symbol.match(/.{1,3}/g);