add ad services and Docker configuration for web app

lib/services/quote_api.dart

@@ -111,7 +111,10 @@ class QuoteGeneratorApi {
 
     final response = await http.post(
       url,
-      headers: {"Content-Type": "application/json"},
+      headers: {
+        "Content-Type": "application/json",
+        "User-Agent": "QuoteGen-Flutter/1.0",
+      },
       body: jsonEncode(requestBody),
     );
 
@@ -127,7 +130,10 @@ class QuoteGeneratorApi {
     final queryString = request.toQueryString();
     final url = Uri.parse("$_baseUrl/generate?$queryString");
 
-    final response = await http.get(url);
+    final response = await http.get(
+      url,
+      headers: {"User-Agent": "QuoteGen-Flutter/1.0"},
+    );
 
     if (response.statusCode == 200) {
       return response.bodyBytes;
@@ -146,7 +152,10 @@ class QuoteGeneratorApi {
   static Future<bool> checkHealth() async {
     try {
       final url = Uri.parse("$_baseUrl/health");
-      final response = await http.get(url);
+      final response = await http.get(
+        url,
+        headers: {"User-Agent": "QuoteGen-Flutter/1.0"},
+      );
 
       if (response.statusCode == 200) {
         final data = jsonDecode(response.body);