feat: audit and purge legacy backend files, stub Phase 2 AI LLM modules, create comprehensive PAGEWISE_API_DOCUMENTATION.md, and wire DPS test seeding

backend/seed.py

@@ -412,8 +412,9 @@ def seed_local_database():
                     dps_session.add(q)
                     q_ids.append(str(q.id))
 
+                dps_id = uuid4()
                 dps = models.DPS(
-                    id=uuid4(),
+                    id=dps_id,
                     date=sheet_date,
                     title=sheet_title,
                     questions=q_ids,
@@ -423,7 +424,22 @@ def seed_local_database():
                     created_by=admin_id,
                 )
                 dps_session.add(dps)
-                print(f"  ✓ DPS seeded: {sheet_title} ({len(q_ids)} questions)")
+
+                # Also create as Test(type='DPS') so /api/tests?type=DPS and CBT engine can run it
+                dps_test = models.Test(
+                    id=dps_id,
+                    title=sheet_title,
+                    type="DPS",
+                    exam_pattern=models.ExamEnum.JEE_MAIN,
+                    sections={"Practice": {"questions": q_ids, "time_limit": 30}},
+                    total_time=30,
+                    difficulty="Medium",
+                    scheduled_date=datetime.combine(sheet_date, datetime.min.time()),
+                    is_active=True,
+                    created_by=admin_id,
+                )
+                dps_session.add(dps_test)
+                print(f"  ✓ DPS & CBT Test seeded: {sheet_title} ({len(q_ids)} questions)")
 
             dps_session.commit()