Implement CSV loading and saving functionality; refactor user list management; update UUID generation and search functions; enhance signal handling in main application.

.vscode/launch.json

@@ -5,7 +5,7 @@
             "name": "Debug",
             "type": "cppdbg",
             "request": "launch",
-            "args": [],
+            "args": ["khkokhot.csv"],
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}",
             "environment": [],

.vscode/settings.json

@@ -8,7 +8,8 @@
         "fcntl.h": "c",
         "file_operations.h": "c",
         "string.h": "c",
-        "termios.h": "c"
+        "termios.h": "c",
+        "typeinfo": "c"
     },
     "C_Cpp.errorSquiggles": "enabled"
 }