App defaults to reading GitHub issues as web URLs

When asked to read a GitHub issue, the app defaults to trying to read it as a webpage - which most of the time fails since issues are usually in private repos.

instead the app should default to resolving all github links via the API, otherwise it just wastes cycles trying and failing to fetch the webpage

---
| Field | Value |
| --- | --- |
| App version | 1.1.10 |
| OS | macOS 26.6.1 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 12 |

从 /chat 路径开始，这里会解析 GitHub issue 链接，然后跟踪应用如何在网页抓取和通过 API 解析之间进行选择。复现 issue 中的私有仓库案例，然后验证 GitHub 链接默认使用 API，不再先尝试一次会失败的网页抓取。

由索引模型根据 Issue 内容生成。