Spread other error information in ErrorMessage

The current Error that can be copied by users, isn't very helpful for
debugging.

We should stringify the entire error, with zodIssues, path, body, etc.
for useful debugging.

src/components/ErrorMessage.svelte

@@ -40,7 +40,11 @@
     </div>
     <div style:max-width="25rem">
       <Command
-        command={JSON.stringify({ message: error.message, stack: error.stack })}
+        command={JSON.stringify({
+          message: error.message,
+          stack: error.stack,
+          ...error,
+        })}
         fullWidth
         showPrompt={false} />
     </div>