update runtime to handle ensureUserExists in edge cases

Author: lalalune

packages/core/src/runtime.ts

@@ -1189,8 +1189,14 @@ export class AgentRuntime implements IAgentRuntime {
                 id: userId,
                 name: name || this.character.name || "Unknown User",
                 username: userName || this.character.username || "Unknown",
-                email: email || this.character.email || userId, // Temporary
-                details: this.character || { summary: "" },
+                // TODO: We might not need these account pieces
+                email: email || this.character.email || userId,
+                // When invoke ensureUserExists and saving account.details
+                // Performing a complete JSON.stringify on character will cause a TypeError: Converting circular structure to JSON error in some more complex plugins.
+                details: this.character ? Object.assign({}, this.character, {
+                    source,
+                    plugins: this.character?.plugins?.map((plugin) => plugin.name),
+                }) : { summary: "" },
             });
             elizaLogger.success(`User ${userName} created successfully.`);
         }