Introduce MistralRequestCoordinator and queued auto-screenshot handling

app/src/main/kotlin/com/google/ai/sample/ScreenCaptureApiClients.kt

@@ -15,6 +15,7 @@ import kotlinx.serialization.json.JsonClassDiscriminator
 import kotlinx.serialization.modules.SerializersModule
 import kotlinx.serialization.modules.polymorphic
 import kotlinx.serialization.modules.subclass
+import com.google.ai.sample.network.MistralRequestCoordinator
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
@@ -70,7 +71,13 @@ data class ServiceMistralResponseMessage(
     val content: String
 )
 
-internal suspend fun callMistralApi(modelName: String, apiKey: String, chatHistory: List<Content>, inputContent: Content): Pair<String?, String?> {
+internal suspend fun callMistralApi(
+    modelName: String,
+    apiKey: String,
+    chatHistory: List<Content>,
+    inputContent: Content,
+    availableApiKeys: List<String> = listOf(apiKey)
+): Pair<String?, String?> {
     var responseText: String? = null
     var errorMessage: String? = null
 
@@ -129,7 +136,16 @@ internal suspend fun callMistralApi(modelName: String, apiKey: String, chatHisto
             .addHeader("Authorization", "Bearer $apiKey")
             .build()
 
-        client.newCall(request).execute().use { response ->
+        val keysForCoordinator = availableApiKeys.filter { it.isNotBlank() }.distinct().ifEmpty { listOf(apiKey) }
+        val coordinated = MistralRequestCoordinator.execute(apiKeys = keysForCoordinator, maxAttempts = maxOf(4, keysForCoordinator.size * 3)) { key ->
+            client.newCall(
+                request.newBuilder()
+                    .header("Authorization", "Bearer $key")
+                    .build()
+            ).execute()
+        }
+
+        coordinated.response.use { response ->
             val responseBody = response.body?.string()
             if (!response.isSuccessful) {
                 Log.e("ScreenCaptureService", "Mistral API Error ($response.code): $responseBody")

app/src/main/kotlin/com/google/ai/sample/ScreenCaptureService.kt

@@ -297,7 +297,16 @@ class ScreenCaptureService : Service() {
                             if (apiProvider == ApiProvider.VERCEL) {
                                 responseText = callVercelApi(applicationContext, modelName, apiKey, chatHistoryDtos, inputContentDto)
                             } else if (apiProvider == ApiProvider.MISTRAL) {
-                                val result = callMistralApi(modelName, apiKey, chatHistory, inputContent)
+                                val availableMistralKeys = ApiKeyManager.getInstance(applicationContext)
+                                    .getApiKeys(ApiProvider.MISTRAL)
+                                    .filter { it.isNotBlank() }
+                                val result = callMistralApi(
+                                    modelName = modelName,
+                                    apiKey = apiKey,
+                                    chatHistory = chatHistory,
+                                    inputContent = inputContent,
+                                    availableApiKeys = availableMistralKeys
+                                )
                                 responseText = result.first
                                 errorMessage = result.second
                             } else if (apiProvider == ApiProvider.PUTER) {