feat: add computer name-based silent login (无感登录)

Implement automatic authentication based on computer name to enable
passwordless login for registered computers with fallback to manual
authentication.

Changes:
- Add SessionManager.login_by_computer_name() for silent login attempt
- Add BIPUsersDAO.authenticate_by_computer_name() for computer name lookup
- Update BIPUsersDAO.create_user() to support optional computer_name parameter
- Update main_ui.py to try silent login before showing login dialog
- Display current computer name in login dialog for user reference

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

db/bip_users_dao.py

@@ -49,6 +49,44 @@ class BIPUsersDAO(BaseDAO):
                 }
         return None
 
+    def authenticate_by_computer_name(self, computer_name: str) -> Optional[Dict[str, Any]]:
+        """
+        Authenticate a user using computer name (silent login)
+
+        Args:
+            computer_name: The computer name to authenticate
+
+        Returns:
+            Dict with user info if authentication successful, None otherwise
+            Returns: {id, username, user_type}
+        """
+        table_name = self._convert_sql('[dbo].[BIPUsers]')
+        placeholder = self._get_placeholder()
+
+        # Note: Column name is 'ComputerNmae' (typo in database schema)
+        if self._db_type == DatabaseType.MYSQL:
+            sql = f"""
+            SELECT ID, UserName, UserType
+            FROM {table_name}
+            WHERE ComputerNmae = {placeholder}
+            """
+        else:
+            sql = f"""
+            SELECT [ID], [UserName], [UserType]
+            FROM {table_name}
+            WHERE [ComputerNmae] = {placeholder}
+            """
+
+        with get_connection() as db:
+            results = db.execute_query(sql, (computer_name,))
+            if results:
+                return {
+                    'id': results[0]['ID'],
+                    'username': results[0]['UserName'],
+                    'user_type': results[0]['UserType']
+                }
+        return None
+
     def get_all_users(self) -> List[Dict[str, Any]]:
         """
         Get all users from the database
@@ -84,14 +122,15 @@ class BIPUsersDAO(BaseDAO):
                 for row in results
             ]
 
-    def create_user(self, username: str, password: str, user_type: str) -> bool:
+    def create_user(self, username: str, password: str, user_type: str, computer_name: str = '') -> bool:
         """
-        Create a new user
+        Create a new user with optional computer name for silent login
 
         Args:
             username: The username (must be unique)
             password: The password (plain text for internal tool)
             user_type: User type ('Admin', 'User', or 'Guest')
+            computer_name: Optional computer name for silent login (default: '')
 
         Returns:
             True if successful, False otherwise
@@ -101,19 +140,35 @@ class BIPUsersDAO(BaseDAO):
 
         # 根据数据库类型选择列名格式
         if self._db_type == DatabaseType.MYSQL:
-            sql = f"""
-            INSERT INTO {table_name} (UserName, Password, UserType)
-            VALUES ({placeholder}, {placeholder}, {placeholder})
-            """
+            if computer_name:
+                sql = f"""
+                INSERT INTO {table_name} (UserName, Password, UserType, ComputerNmae)
+                VALUES ({placeholder}, {placeholder}, {placeholder}, {placeholder})
+                """
+                params = (username, password, user_type, computer_name)
+            else:
+                sql = f"""
+                INSERT INTO {table_name} (UserName, Password, UserType)
+                VALUES ({placeholder}, {placeholder}, {placeholder})
+                """
+                params = (username, password, user_type)
         else:
-            sql = f"""
-            INSERT INTO {table_name} ([UserName], [Password], [UserType])
-            VALUES ({placeholder}, {placeholder}, {placeholder})
-            """
+            if computer_name:
+                sql = f"""
+                INSERT INTO {table_name} ([UserName], [Password], [UserType], [ComputerNmae])
+                VALUES ({placeholder}, {placeholder}, {placeholder}, {placeholder})
+                """
+                params = (username, password, user_type, computer_name)
+            else:
+                sql = f"""
+                INSERT INTO {table_name} ([UserName], [Password], [UserType])
+                VALUES ({placeholder}, {placeholder}, {placeholder})
+                """
+                params = (username, password, user_type)
 
         try:
             with get_connection() as db:
-                db.execute_update(sql, (username, password, user_type))
+                db.execute_update(sql, params)
                 return True
         except Exception as e:
             print(f"Error creating user: {e}")