fix(core/binding): 将 action_arg 改为值类型避免悬空指针问题

src/core/binding.c

@@ -167,7 +167,7 @@ bool binding_table_add_bind(
   zdwm_binding_mode_id_t mode_id,
   const char *key_sequence,
   zdwm_action_fn fn,
-  zdwm_action_arg_t *arg
+  zdwm_action_arg_t arg
 ) {
   binding_mode_t *mode = binding_table_get_mode(table, mode_id);
   if (!mode) return false;

src/core/binding.h

@@ -13,7 +13,7 @@ typedef struct key_binding_t {
   modifier_mask_t modifiers;
   keysym_t keysym;
   zdwm_action_fn *fn;
-  zdwm_action_arg_t *arg;
+  zdwm_action_arg_t arg;
 } key_binding_t;
 
 /**
@@ -47,7 +47,7 @@ bool binding_table_add_bind(
   zdwm_binding_mode_id_t mode_id,
   const char *key_sequence,
   zdwm_action_fn fn,
-  zdwm_action_arg_t *arg
+  zdwm_action_arg_t arg
 );
 
 /**

src/core/policy.c

@@ -27,7 +27,7 @@ static void route_key_press(
   for (size_t i = 0; i < count; ++i) {
     auto binding = &bindings[i];
     if (binding->modifiers == e->modifiers && binding->keysym == e->keysym) {
-      binding->fn(action_ctx, binding->arg);
+      binding->fn(action_ctx, &binding->arg);
     }
   }
 }