feat: 添加侧边栏贡献按钮，优化打开上传页面逻辑，更新相关测试

sidepanel/sidepanel.css

@@ -118,6 +118,30 @@ header {
 
 .header-left svg { color: var(--blue); }
 
+.header-icon-link {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0;
+  border: none;
+  background: transparent;
+  color: inherit;
+  cursor: pointer;
+  flex-shrink: 0;
+  appearance: none;
+}
+
+.header-icon-link:hover svg {
+  color: var(--text-primary);
+}
+
+.header-icon-link:focus-visible,
+.header-version-link:focus-visible {
+  outline: 2px solid color-mix(in srgb, var(--blue) 28%, transparent);
+  outline-offset: 2px;
+  border-radius: var(--radius-sm);
+}
+
 .header-version-block {
   min-width: 0;
   display: flex;
@@ -144,6 +168,22 @@ header {
   text-overflow: ellipsis;
 }
 
+.header-version-link {
+  display: block;
+  padding: 0;
+  border: none;
+  background: transparent;
+  font: inherit;
+  text-align: left;
+  cursor: pointer;
+  appearance: none;
+}
+
+.header-version-link:hover {
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
 .header-version-title.is-version-label { color: var(--blue); }
 .header-version-title.is-update-available { color: var(--orange); }
 .header-version-title.is-check-failed { color: var(--text-primary); }