feat: add Alibaba Cloud Coding Plan support

Add support for Alibaba Cloud Bailian Coding Plan, a coding-focused AI service
that provides fixed monthly pricing for multiple models.

Changes:
- Add alicloud provider with OpenAI-compatible API endpoint
- Support 8 models: qwen3.5-plus, kimi-k2.5, glm-5, MiniMax-M2.5,
  qwen3-max, qwen3-coder-next, qwen3-coder-plus, glm-4.7
- Use "ali" as provider alias (ali/model format)
- Add API key validation and connection testing
- Add frontend provider definition with "ALi" text icon

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

open-sse/config/constants.js

@@ -174,6 +174,11 @@ export const PROVIDERS = {
       "User-Agent": "connect-es/1.6.1"
     },
     clientVersion: "1.1.3"
+  },
+  alicloud: {
+    baseUrl: "https://coding.dashscope.aliyuncs.com/v1/chat/completions",
+    format: "openai",
+    headers: {}
   }
 };