fix: remove trailing spacers before PDF build to avoid blank last page

app/services/pdf_generator.py

@@ -278,7 +278,7 @@ def generate_pdf(plan_id, student_name, content, output_dir, rendered_report=Non
             return
         c.saveState()
         try:
-            c.setFont("Chinese", 14)
+            c.setFont("Chinese", 56)
             # 浅灰色半透明
             c.setFillColor(colors.Color(0.6, 0.6, 0.6, alpha=0.25))
             # 旋转45度
@@ -290,5 +290,9 @@ def generate_pdf(plan_id, student_name, content, output_dir, rendered_report=Non
             pass
         c.restoreState()
 
+    # 移除末尾的空白元素（避免产生多余空白页）
+    while pdf.elements and isinstance(pdf.elements[-1], Spacer):
+        pdf.elements.pop()
+
     doc.build(pdf.elements, onFirstPage=draw_watermark, onLaterPages=draw_watermark)
     return output_path

config/api_config.json

@@ -8,5 +8,6 @@
   "model": "MiniMax-M2.7-highspeed",
   "temperature": 0.1,
   "prompt_template": "",
-  "api_key": "sk-cp-Mj6FHASGAcdc1IhpetY7z4lXCgbkoGAkMbViODPHiVdC-NerbqKRW8ZTCuFliDA9JukoB56ILEYUhDKH2QUJq-xt1ZYNStQ-HNgjRvXIq0H4gOgoxy26xuA"
+  "api_key": "sk-cp-Mj6FHASGAcdc1IhpetY7z4lXCgbkoGAkMbViODPHiVdC-NerbqKRW8ZTCuFliDA9JukoB56ILEYUhDKH2QUJq-xt1ZYNStQ-HNgjRvXIq0H4gOgoxy26xuA",
+  "watermark_text": "有音教育·艺超音乐培训"
 }