feat: embed a Flutter G4F client with Cronet, cookie jar, and origin WebView

Port the Oracle off the Python g4f container onto on-device providers: Chromium HTTP via Cronet, a shared cookie session, IterList retry, hosted OpenAI-compat aggregators, and same-origin WebView fallbacks instead of CORS fetch.

android/app/build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 
 android {
     namespace = "com.example.words999.words999"
-    compileSdk = flutter.compileSdkVersion
+    compileSdk = 36
     ndkVersion = flutter.ndkVersion
 
     compileOptions {

android/build.gradle.kts

@@ -19,6 +19,20 @@ subprojects {
     project.evaluationDependsOn(":app")
 }
 
+gradle.projectsEvaluated {
+    rootProject.subprojects.forEach { proj ->
+        val android = proj.extensions.findByName("android") ?: return@forEach
+        try {
+            android.javaClass.getMethod("setCompileSdk", Int::class.javaPrimitiveType).invoke(android, 36)
+        } catch (_: Throwable) {
+            try {
+                android.javaClass.getMethod("setCompileSdkVersion", Int::class.javaPrimitiveType).invoke(android, 36)
+            } catch (_: Throwable) {
+            }
+        }
+    }
+}
+
 tasks.register<Delete>("clean") {
     delete(rootProject.layout.buildDirectory)
 }