fix(mobile): drive learning search from assignments

mobile-uni/src/services/learning.ts

@@ -0,0 +1,44 @@
+export interface LearningTopicAssignment {
+  source?: string | null;
+  status?: string | null;
+  scenarioName?: string | null;
+}
+
+const normalized = (value?: string | null) => value?.trim() || '';
+
+export const selectLearningTopic = (
+  assignments: readonly LearningTopicAssignment[],
+  fallbackTopic: string
+) => {
+  const scenarioAssignments = assignments.filter((item) =>
+    normalized(item.source) !== 'daily' && Boolean(normalized(item.scenarioName))
+  );
+  const selected = scenarioAssignments.find((item) => normalized(item.status) !== '已完成')
+    || scenarioAssignments[0];
+
+  return normalized(selected?.scenarioName) || fallbackTopic;
+};
+
+export const buildLearningTopics = (
+  assignments: readonly LearningTopicAssignment[],
+  fallbackTopic: string,
+  quickQuestions: readonly string[]
+) => {
+  const values = [
+    fallbackTopic,
+    ...assignments
+      .filter((item) => normalized(item.source) !== 'daily')
+      .map((item) => normalized(item.scenarioName)),
+    ...quickQuestions
+  ];
+  const topics: string[] = [];
+
+  values.forEach((value) => {
+    const topic = normalized(value);
+    if (topic && !topics.includes(topic)) {
+      topics.push(topic);
+    }
+  });
+
+  return topics;
+};