remove: drop support for claude-2 and claude-1 series models

- Remove claude-instant-1.2, claude-2, claude-2.0, claude-2.1 from model lists
- Remove /v1/complete endpoint support (legacy completion API)
- Remove RequestModeCompletion and related code paths
- Simplify handler functions by removing requestMode parameter
- Update all channel adaptors that referenced claude handlers

web/src/helpers/render.jsx

@@ -571,7 +571,6 @@ export const modelColorMap = {
   'claude-3-opus-20240229': 'rgb(255,132,31)', // 橙红色
   'claude-3-sonnet-20240229': 'rgb(253,135,93)', // 橙色
   'claude-3-haiku-20240307': 'rgb(255,175,146)', // 浅橙色
-  'claude-2.1': 'rgb(255,209,190)', // 浅橙色（略有区别）
 };
 
 export function modelToColor(modelName) {