feat: replace static Swagger UI server selector with dynamic client-side detection

- Update openapi.yaml to use single placeholder server URL
- Add swagger-server-detection.js to auto-detect current server URL from window.location
- Configure protocol, host, and port detection based on browser connection
- Fallback to placeholder URL if detection fails
- Include detection script in both app.js and index.js Swagger UI configurations
- /api/swagger.json endpoint returns static placeholder for external consumers

server/index.js

@@ -300,7 +300,8 @@ app.use('/api/swagger', swaggerUi.serve, swaggerUi.setup(swaggerSpec, {
   customSiteTitle: 'sofarr API Documentation',
   customCss: '.swagger-ui .topbar { display: none }',
   customJs: [
-    '/swagger-auth-banner.js'
+    '/swagger-auth-banner.js',
+    '/swagger-server-detection.js'
   ]
 }));