fix: 修复Python模块导入错误并优化Chat功能

- 修复 core/agents/api 模块导入问题
- 优化 ChatInput 组件交互体验
- 增强 agent_handler 和 agent_service 功能
- 调整 Chat 页面样式和布局

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/agents/api/server.py

@@ -0,0 +1,26 @@
+"""X-Agents API Server."""
+
+import sys
+sys.path.insert(0, 'D:/Code/Project/X-Agents/core')
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from .routes import router
+
+app = FastAPI(title="X-Agents API")
+
+# Add CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include the router
+app.include_router(router)
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host="0.0.0.0", port=8001)