fix: update async-http-client to 3.0.6 and change dependency scopes to api

- Update async-http-client from 3.0.1 to 3.0.6 (addresses Issue #79)
- Change httpclient, async-http-client, and gson from 'implementation'
  to 'api' scope since they appear in public method signatures (Issue #78)

Closes #78
Closes #79

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: git-wright

build.gradle

@@ -41,9 +41,10 @@ java {
 }
 
 dependencies {
-    implementation 'org.apache.httpcomponents:httpclient:4.5.13'
-    implementation 'org.asynchttpclient:async-http-client:3.0.1'
-    implementation 'com.google.code.gson:gson:2.8.9'
+    // These are 'api' because they appear in public method signatures (Issue #78)
+    api 'org.apache.httpcomponents:httpclient:4.5.13'
+    api 'org.asynchttpclient:async-http-client:3.0.6'  // Updated from 3.0.1 (Issue #79)
+    api 'com.google.code.gson:gson:2.8.9'
 
     // Force Netty upgrade to resolve CVEs
     implementation platform("io.netty:netty-bom:${nettyVersion}")