agent: v3.0 — fix cfg scope bug in execute_command (update + shell commands)

self_update(cfg) and shell allow_shell_commands check both referenced cfg
from run() scope, but execute_command() is a standalone function. Fixed by
calling load_config() locally in each branch that needs it.

agent/jarvis-agent.py

@@ -525,12 +525,14 @@ def execute_command(cmd: dict) -> dict:
             return {"success": r.returncode == 0, "output": r.stdout}
 
         elif cmd_type == "update":
-            updated = self_update(cfg)
+            _cfg = load_config()
+            updated = self_update(_cfg)
             return {"success": True, "updated": updated}
 
         elif cmd_type == "shell":
             # Guard reads LOCAL config, not the server-supplied payload
-            if not cfg.get("allow_shell_commands", False):
+            _cfg = load_config()
+            if not _cfg.get("allow_shell_commands", False):
                 return {"success": False, "error": "Shell commands not enabled in agent config"}
             cmd_str = cmd_data.get("command", "")
             r = subprocess.run(cmd_str, shell=True, capture_output=True, text=True, timeout=30)