feat(about): 增强 GitHub 数据获取与降级机制

- 为用户数据请求添加本地 JSON 降级方案
- 为仓库数据请求添加本地 JSON 降级方案
- 拆分用户与仓库数据获取逻辑，提高可维护性
- 增加对 AbortError 等异常情况的处理
- 移除全局异常处理中的默认配置兜底逻辑
- 优化超时设置，区分不同资源的加载时间限制

js/about.js

@@ -284,8 +284,26 @@ class DataManager {
 
         try {
             // Parallel Fetch with timeout
+            let userData, repoData;
+
+            try {
                 const uRes = await this.fetchWithTimeout(`https://api.github.com/users/${user}`, { timeout: 1000 });
-            const userData = uRes.ok ? await uRes.json() : (window.SiteConfig?.defaults?.user);
+                if (uRes.ok) {
+                    userData = await uRes.json();
+                } else {
+                    const fallbackUser = await this.fetchWithTimeout("./data/github_user.json", { timeout: 200 });
+                    userData = await fallbackUser.json();
+                }
+            } catch (err) {
+                // Handle abort errors and other fetch errors
+                if (err.name === 'AbortError') {
+                    console.warn("GitHub user fetch aborted, using fallback data");
+                }
+                const fallbackUser = await this.fetchWithTimeout("./data/github_user.json", { timeout: 200 });
+                userData = await fallbackUser.json();
+            }
+
+            try {
                 let allRepos = [];
                 let page = 1;
                 const perPage = 100;
@@ -298,7 +316,21 @@ class DataManager {
                     if (repos.length < perPage || allRepos.length >= 500) break; // 足量
                     page++;
                 }
-            let repoData = allRepos.length ? allRepos : (window.SiteConfig?.defaults?.repos);
+
+                if (allRepos.length) {
+                    repoData = allRepos;
+                } else {
+                    const fallbackRepos = await this.fetchWithTimeout("./data/github_repos.json", { timeout: 300 });
+                    repoData = await fallbackRepos.json();
+                }
+            } catch (err) {
+                // Handle abort errors and other fetch errors
+                if (err.name === 'AbortError') {
+                    console.warn("GitHub repos fetch aborted, using fallback data");
+                }
+                const fallbackRepos = await this.fetchWithTimeout("./data/github_repos.json", { timeout: 300 });
+                repoData = await fallbackRepos.json();
+            }
 
             // 过滤掉fork项目并按星数排序
             if (Array.isArray(repoData)) {
@@ -329,10 +361,8 @@ class DataManager {
 
         } catch (e) {
             console.warn("GH API Fail", e);
-            const  githubUser = await this.fetchWithTimeout("./data/github_user.json", { timeout: 1000 });
+            this.renderUser(window.SiteConfig?.defaults?.user);
-            const githubRepos =  await this.fetchWithTimeout("./data/github_repos.json", { timeout: 1000 });
+            this.renderRepos(window.SiteConfig?.defaults?.repos);
-            this.renderUser(githubUser ? githubUser : window.SiteConfig?.defaults?.user);
-            this.renderRepos(githubRepos ? githubRepos : window.SiteConfig?.defaults?.repos);
         }
     }