added completion info to client api

docs/android-questionnaire-api.md

@@ -176,8 +176,20 @@ Success:
   "ok": true,
   "data": {
     "clients": [
-      "CLIENT-001",
-      "CLIENT-002"
+      {
+        "clientCode": "CLIENT-001",
+        "completedQuestionnaires": [
+          {
+            "questionnaireID": "questionnaire_1_demographic_information",
+            "sumPoints": 42,
+            "completedAt": 1714471800
+          }
+        ]
+      },
+      {
+        "clientCode": "CLIENT-002",
+        "completedQuestionnaires": []
+      }
     ]
   }
 }
@@ -185,7 +197,12 @@ Success:
 
 Fields:
 
-- `clients`: array of client code strings assigned to the coach, ordered alphabetically.
+- `clients`: array of client objects assigned to the coach, ordered alphabetically by `clientCode`.
+- `clients[].clientCode`: the client's code string.
+- `clients[].completedQuestionnaires`: array of questionnaires already completed by this client. Empty array if none.
+- `clients[].completedQuestionnaires[].questionnaireID`: the questionnaire ID, matching the IDs from the questionnaire list endpoint.
+- `clients[].completedQuestionnaires[].sumPoints`: total points from the last upload for this questionnaire.
+- `clients[].completedQuestionnaires[].completedAt`: Unix timestamp (seconds) of when the questionnaire was completed, or `null` if not recorded.
 
 Common failures:
 
@@ -411,7 +428,18 @@ data class SubmitQuestionnaireResponse(
 )
 
 data class ClientsResponse(
-    val clients: List<String>
+    val clients: List<ClientInfo>
+)
+
+data class ClientInfo(
+    val clientCode: String,
+    val completedQuestionnaires: List<CompletedQuestionnaire> = emptyList()
+)
+
+data class CompletedQuestionnaire(
+    val questionnaireID: String,
+    val sumPoints: Int,
+    val completedAt: Long?
 )
 ```
 
@@ -453,4 +481,4 @@ interface QuestionnaireApi {
 }
 ```
 
-Pass the token as `Bearer $token`.
+Pass the token as `Bearer $token`.