fix: Response wrapping, error logging, and controller hardening (COA 3)

- HttpExceptionFilter: Log actual error details for non-HttpExceptions (was silently swallowing 500s)
- ServersService: Return null fields instead of 404 for new licenses without servers
- NotificationsController: Wrap config responses as { config } to match frontend expectations
- WebstoreController: Wrap config responses as { config } to match frontend expectations
- ChatController: Replace ParseIntPipe with manual parseInt (400 on missing optional param)
- WipesController: Same ParseIntPipe fix for history limit param

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

backend-nest/src/modules/servers/servers.service.ts

@@ -17,7 +17,8 @@ export class ServersService {
   ) {}
 
   /**
-   * Get server connection and config for a license
+   * Get server connection and config for a license.
+   * Returns null fields if no server has been set up yet.
    */
   async getServer(licenseId: string) {
     const connection = await this.connectionRepo.findOne({
@@ -28,11 +29,11 @@ export class ServersService {
       where: { license_id: licenseId },
     });
 
-    if (!connection || !config) {
-      throw new NotFoundException('Server not found for this license');
-    }
-
-    return { connection, config };
+    return {
+      connection: connection || null,
+      config: config || null,
+      setup_required: !connection || !config,
+    };
   }
 
   /**