feat: add floating provider navigation sidebar to AI providers page

src/components/providers/ProviderNav/ProviderNav.module.scss

@@ -0,0 +1,83 @@
+@use '../../../styles/variables' as *;
+
+.navContainer {
+  position: fixed;
+  right: 24px;
+  top: 50%;
+  transform: translateY(-50%);
+  z-index: 50;
+  pointer-events: auto;
+}
+
+.navList {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  padding: 12px 8px;
+  background: rgba(255, 255, 255, 0.7);
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+  border: 1px solid rgba(255, 255, 255, 0.3);
+  border-radius: 16px;
+  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.1);
+}
+
+.navItem {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 40px;
+  height: 40px;
+  padding: 0;
+  border: none;
+  background: transparent;
+  border-radius: 10px;
+  cursor: pointer;
+  transition: background-color 0.2s ease, transform 0.15s ease;
+
+  &:hover {
+    background: rgba(0, 0, 0, 0.06);
+    transform: scale(1.08);
+  }
+
+  &:active {
+    transform: scale(0.95);
+  }
+}
+
+.icon {
+  width: 28px;
+  height: 28px;
+  object-fit: contain;
+}
+
+.active {
+  background: rgba(59, 130, 246, 0.15);
+  box-shadow: inset 0 0 0 2px var(--primary-color);
+}
+
+// 暗色主题适配
+:global([data-theme='dark']) {
+  .navList {
+    background: rgba(30, 30, 30, 0.7);
+    border-color: rgba(255, 255, 255, 0.1);
+    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
+  }
+
+  .navItem {
+    &:hover {
+      background: rgba(255, 255, 255, 0.1);
+    }
+  }
+
+  .active {
+    background: rgba(59, 130, 246, 0.25);
+  }
+}
+
+// 小屏幕隐藏悬浮导航
+@media (max-width: 1200px) {
+  .navContainer {
+    display: none;
+  }
+}