feat: 问题数据迁移到数据库；学员详情页URL导航改造；侧边栏统一

- 问题从文件系统迁移到数据库 problems 表
- 移除 PROBLEMS_DIR 配置和文件读取逻辑
- student.html 完整重写：编辑/添加/删除问题，生成方案进度显示
- 学员详情页支持独立URL访问 (/student/<id>)
- 统一侧边栏到 base.html
- 更新文档：DEPLOYMENT_SOP, MODELS, STRUCTURE, FRONTEND_ARCH
- 部署到生产环境 v1.2.0

app/models.py

@@ -114,6 +114,15 @@ class Student(db.Model):
     class_obj = db.relationship("Class", backref="students")
 
     def to_dict(self):
+        # 获取问题列表，按严重程度排序（严重 > 中等 > 轻微）
+        severity_order = {"严重": 0, "中等": 1, "轻微": 2}
+        problems_list = sorted(
+            self.problems.all(),
+            key=lambda p: (severity_order.get(p.severity, 1), p.created_at)
+        )
+        # 通过关联获取问题名称
+        problem_names = [p.problem.name if p.problem else p.problem_name for p in problems_list]
+
         return {
             "id": self.id,
             "name": self.name,
@@ -127,10 +136,33 @@ class Student(db.Model):
             if self.created_at
             else None,
             "problem_count": self.problems.count(),
+            "problem_names": problem_names,  # 问题名称列表（按严重程度排序）
             "plan_count": self.plans.count(),
         }
 
 
+class Problem(db.Model):
+    """问题表"""
+
+    __tablename__ = "problems"
+
+    id = db.Column(db.Integer, primary_key=True)
+    no = db.Column(db.String(10), unique=True, nullable=False)  # 编号：01, 02...
+    name = db.Column(db.String(100), nullable=False)  # 问题名称
+    category = db.Column(db.String(50), default="技术类")  # 分类
+    content = db.Column(db.Text)  # 问题详细内容
+    created_at = db.Column(db.DateTime, default=datetime.now)
+    updated_at = db.Column(db.DateTime, default=datetime.now, onupdate=datetime.now)
+
+    def to_dict(self):
+        return {
+            "id": self.id,
+            "no": self.no,
+            "name": self.name,
+            "category": self.category,
+        }
+
+
 class StudentProblem(db.Model):
     """学员问题记录表"""
 
@@ -138,17 +170,21 @@ class StudentProblem(db.Model):
 
     id = db.Column(db.Integer, primary_key=True)
     student_id = db.Column(db.Integer, db.ForeignKey("students.id"), nullable=False)
-    problem_id = db.Column(db.String(50), nullable=False)  # 如 "01_手小"
-    problem_name = db.Column(db.String(100), nullable=False)  # 如 "手小"
+    problem_id = db.Column(db.Integer, db.ForeignKey("problems.id"), nullable=False)  # 外键
     severity = db.Column(db.String(10), nullable=False)  # 轻微/中等/严重
     level = db.Column(db.String(20))  # 启蒙/入门/进阶/熟练/精通
     created_at = db.Column(db.DateTime, default=datetime.now)
 
+    # 关联到 Problem
+    problem = db.relationship("Problem", foreign_keys=[problem_id])
+
     def to_dict(self):
         return {
             "id": self.id,
-            "problem_id": self.problem_id,
-            "problem_name": self.problem_name,
+            "student_id": self.student_id,
+            "problem_id": self.problem_id,  # 外键关联到 problems.id
+            "problem_name": self.problem.name if self.problem else None,
+            "problem_no": self.problem.no if self.problem else None,
             "severity": self.severity,
             "level": self.level,
         }
@@ -161,14 +197,43 @@ class PracticePlan(db.Model):
 
     id = db.Column(db.Integer, primary_key=True)
     student_id = db.Column(db.Integer, db.ForeignKey("students.id"), nullable=False)
+    template_id = db.Column(db.Integer, db.ForeignKey("templates.id"), nullable=True)  # 使用的AI提示词模板
+    is_typical = db.Column(db.Boolean, default=False, nullable=False)  # 是否为典型方案
     content = db.Column(db.Text, nullable=False)  # JSON格式存储方案内容
     created_at = db.Column(db.DateTime, default=datetime.now)
 
+    # 关联
+    template = db.relationship("Template", foreign_keys=[template_id])
+
     def to_dict(self):
+        import json as json_module
+        content_obj = {}
+        try:
+            content_obj = json_module.loads(self.content) if self.content else {}
+        except:
+            pass
+
+        # 从 content 中提取问题列表
+        problems = content_obj.get("problems", [])
+        problem_names = [p.get("name", "") for p in problems] if problems else []
+
+        # 获取模板名称
+        template_name = self.template.name if self.template else None
+
+        # 获取学员班级
+        class_name = None
+        if self.student and self.student.class_obj:
+            class_name = self.student.class_obj.name
+
         return {
             "id": self.id,
             "student_id": self.student_id,
             "student_name": self.student.name if self.student else "",
+            "class_name": class_name,
+            "template_id": self.template_id,
+            "template_name": template_name,
+            "is_typical": self.is_typical,
+            "problem_names": problem_names,
             "created_at": self.created_at.strftime("%Y-%m-%d %H:%M")
             if self.created_at
             else None,