修复验收：修正最终验收证据问题

scripts/qa/round2_integrated_runner.py

@@ -26,16 +26,30 @@ os.makedirs(REPORT_DIR, exist_ok=True)
 # 统一前缀
 DATA_PREFIX = "QA_R2_"
 
+def get_qa_password():
+    env_file = os.path.expanduser("~/.railwaysystem-qa.env")
+    if os.path.exists(env_file):
+        with open(env_file, 'r', encoding='utf-8') as f:
+            for line in f:
+                if line.strip().startswith("QA_ADMIN_PASSWORD="):
+                    return line.strip().split("=", 1)[1].strip().strip('"')
+    pwd = os.environ.get("QA_ADMIN_PASSWORD")
+    if not pwd:
+        raise RuntimeError("QA_ADMIN_PASSWORD is required and must be configured in environment or ~/.railwaysystem-qa.env")
+    return pwd
+
+QA_DEFAULT_PWD = get_qa_password()
+
 # 测试用户与凭据
 USER_CREDENTIALS = {
-    "admin": ("admin", "admin123"),
-    "train_admin": ("qa_train_admin", "admin123"),
-    "teacher_a": ("qa_teacher_a", "admin123"),
-    "teacher_b": ("qa_teacher_b", "admin123"),
-    "student_a": ("qa_student_a", "admin123"),
-    "student_b": ("qa_student_b", "admin123"),
-    "admin_teacher": ("qa_admin_teacher", "admin123"),
-    "role_nobody": ("qa_role_nobody", "admin123")
+    "admin": ("admin", QA_DEFAULT_PWD),
+    "train_admin": ("qa_train_admin", QA_DEFAULT_PWD),
+    "teacher_a": ("qa_teacher_a", QA_DEFAULT_PWD),
+    "teacher_b": ("qa_teacher_b", QA_DEFAULT_PWD),
+    "student_a": ("qa_student_a", QA_DEFAULT_PWD),
+    "student_b": ("qa_student_b", QA_DEFAULT_PWD),
+    "admin_teacher": ("qa_admin_teacher", QA_DEFAULT_PWD),
+    "role_nobody": ("qa_role_nobody", QA_DEFAULT_PWD)
 }
 
 TOKENS = {}