add test module

android/README.md

@@ -2,7 +2,7 @@
 
 Android SDK for online oral-training video playback. It provides an embeddable
 Media3/ExoPlayer player, streaming cache, tablet gestures, sentence navigation,
-and a placeholder interface for future imitation-quality scoring.
+the server video catalog, and remote imitation-quality assessment.
 
 ## Modules
 
@@ -93,11 +93,36 @@ Override the service only when a staging or private deployment is required:
 OralTrainerSdk.init(
     context,
     OralTrainerSdkConfig(
-        sentenceBoundaryApiBaseUrl = "https://video_service.d1kt.cn"
+        sentenceBoundaryApiBaseUrl = "https://video_service.d1kt.cn",
+        assessmentApiKey = BuildConfig.ORAL_TRAINER_CLIENT_KEY,
     )
 )
 ```
 
+## Video Catalog
+
+The SDK loads ready videos from `GET /api/v1/videos` and resolves both absolute
+and relative stream URLs:
+
+```kotlin
+sdk.videoCatalogApi.fetch(object : VideoCatalogCallback {
+    override fun onSuccess(videos: List<TrainingVideoSummary>) {
+        val video = videos.first()
+        sdk.sentenceBoundaryApi.fetch(video.videoHash, object : SentenceBoundaryApiCallback {
+            override fun onSuccess(result: SentenceBoundaryApiResult) {
+                controller.loadItem(video.toTrainingMediaItem(result.sentences))
+            }
+
+            override fun onError(error: Throwable) {
+                controller.loadItem(video.toTrainingMediaItem())
+            }
+        })
+    }
+
+    override fun onError(error: Throwable) = Unit
+})
+```
+
 ## Local Video Testing
 
 The computer path `/Users/...` is not visible to an Android device. For a
@@ -110,19 +135,40 @@ service and pass its URL as `TrainingMediaItem.uri`. The SDK streams it and
 caches downloaded ranges locally. Copying large 4K files to each device is
 better reserved for explicitly offline courses.
 
-## Future Imitation Scoring
+## Remote Imitation Scoring
 
-Provide an implementation of `ImitationQualityAssessor` when the speech
-assessment algorithm is ready:
+Create the controller with the built-in remote assessor:
 
 ```kotlin
+val remoteAssessor = sdk.createRemoteImitationQualityAssessor()
 val controller = sdk.createController(
-    imitationAssessor = MyImitationQualityAssessor()
+    imitationAssessor = remoteAssessor
 )
 ```
 
 Then call `assessCurrentSentence(recordingUri, callback)` after the student
-records a sentence.
+records a sentence. The current `TrainingMediaItem.id` must be the server video
+SHA-256, which is already true for items created by `TrainingVideoSummary`:
+
+```kotlin
+controller.assessCurrentSentence(
+    recordingUri = recordingUri,
+    locale = "en",
+    callback = object : ImitationAssessmentCallback {
+        override fun onResult(result: ImitationAssessmentResult) {
+            val passed = result.passed == true
+            val score = result.overallScore
+            val durationRatio = result.durationRatio
+        }
+
+        override fun onError(error: Throwable) = Unit
+    }
+)
+```
+
+The server returns content, completeness, fluency, duration, pause, and speech
+rate scores. Phoneme pronunciation and prosody are nullable until the dedicated
+models are enabled.
 
 ## Build