增加一个 source 来源 ai 的题目生成 pdf自检

app/Http/Controllers/Api/QuestionPdfController.php

@@ -45,6 +45,7 @@ class QuestionPdfController extends Controller
             'teacher_name' => 'nullable|string|max:50',
             'paper_name' => 'nullable|string|max:100',
             'include_grading' => 'nullable|boolean',
+            'source' => 'nullable|string|in:default,ai', // 题库来源：default=默认表(questions_tem)，ai=ai表(questions_ai)
         ]);
 
         if ($validator->fails()) {
@@ -62,17 +63,21 @@ class QuestionPdfController extends Controller
         $teacherName = $request->input('teacher_name', '');
         $paperName = $request->input('paper_name', '专项练习');
         $includeGrading = $request->input('include_grading', false);
+        $source = $request->input('source', 'default'); // 题库来源：default=questions_tem, ai=questions_ai
 
         Log::info('生成指定题目PDF', [
             'question_ids' => $questionIds,
             'student_id' => $studentId,
             'count' => count($questionIds),
+            'source' => $source,
         ]);
 
         try {
-            // 1. Fetch questions from database (使用 questions_temp 临时表)
+            // 1. Fetch questions from database
+            $tableName = $source === 'ai' ? 'questions_ai' : 'questions_tem';
+
             $questions = DB::connection('remote_mysql')
-                ->table('questions_tem')
+                ->table($tableName)
                 ->whereIn('id', $questionIds)
                 ->get();