feat: add Universal Provider feature (#348)

* feat: add Universal Provider feature

- Add Universal Provider data structures and type definitions
- Implement backend CRUD operations and sync functionality
- Add frontend UI components (UniversalProviderPanel, Card, FormModal)
- Add NewAPI icon and preset configuration
- Support cross-app (Claude/Codex/Gemini) configuration sync
- Add website URL field for providers
- Implement real-time refresh via event notifications
- Add i18n support (Chinese/English/Japanese)

* feat: integrate universal provider presets into add provider dialog

- Add universal provider presets (NewAPI, Custom Gateway) to preset selector
- Show universal presets with Layers icon badge in preset selector
- Open UniversalProviderFormModal when universal preset is clicked
- Pass initialPreset to auto-fill form when opened from add dialog
- Add i18n keys for addSuccess/addFailed messages
- Keep separate universal provider panel for management

* refactor: move universal provider management to add dialog

- Remove Layers button from main navigation header
- Add 'Manage' button next to universal provider presets
- Open UniversalProviderPanel from within add provider dialog
- Add i18n keys for 'manage' in all locales

* style: display universal provider presets on separate line

- Move universal provider section to a new row with border separator
- Add label '统一供应商:' to clarify the section

* style: unify universal provider label style with preset label

- Use FormLabel component for consistent styling
- Add background to 'Manage' button matching preset buttons
- Update icon size and button padding for consistency

* feat: add sync functionality and JSON preview for Universal Provider

* fix: add missing in_failover_queue field to Provider structs

After rebasing to main, the Provider struct gained a new
`in_failover_queue` field. This fix adds the missing field
to the three to_*_provider() methods in UniversalProvider.

* refactor: redesign AddProviderDialog with tab-based layout

- Add tabs to separate app-specific providers and universal providers
- Move "Add Universal Provider" button from panel header to footer
- Remove unused handleAdd callback and clean up imports
- Update emptyHint i18n text to reference the footer button

* fix: append /v1 suffix to Codex base_url in Universal Provider

Codex uses OpenAI-compatible API which requires the /v1 endpoint suffix.
The Universal Provider now automatically appends /v1 to base_url when
generating Codex provider config if not already present.

- Handle trailing slashes to avoid double slashes
- Apply fix to both backend (to_codex_provider) and frontend preview

* feat: auto-sync universal provider to apps on creation

Previously, users had to manually click sync after adding a universal
provider. Now it automatically syncs to Claude/Codex/Gemini on creation,
providing a smoother user experience.

---------

Co-authored-by: Jason <farion1231@gmail.com>

src/components/universal/UniversalProviderCard.tsx

@@ -0,0 +1,115 @@
+import { useTranslation } from "react-i18next";
+import { Edit2, Trash2, RefreshCw, Globe } from "lucide-react";
+import { Button } from "@/components/ui/button";
+import { ProviderIcon } from "@/components/ProviderIcon";
+import type { UniversalProvider } from "@/types";
+
+interface UniversalProviderCardProps {
+  provider: UniversalProvider;
+  onEdit: (provider: UniversalProvider) => void;
+  onDelete: (id: string) => void;
+  onSync: (id: string) => void;
+}
+
+export function UniversalProviderCard({
+  provider,
+  onEdit,
+  onDelete,
+  onSync,
+}: UniversalProviderCardProps) {
+  const { t } = useTranslation();
+
+  // 获取启用的应用列表
+  const enabledApps: string[] = [
+    provider.apps.claude ? "Claude" : null,
+    provider.apps.codex ? "Codex" : null,
+    provider.apps.gemini ? "Gemini" : null,
+  ].filter((app): app is string => app !== null);
+
+  return (
+    <div className="group relative rounded-xl border border-border/50 bg-card p-4 transition-all hover:border-border hover:shadow-md">
+      {/* 头部：图标和名称 */}
+      <div className="flex items-start justify-between">
+        <div className="flex items-center gap-3">
+          <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-accent">
+            <ProviderIcon icon={provider.icon} name={provider.name} size={24} />
+          </div>
+          <div>
+            <h3 className="font-semibold text-foreground">{provider.name}</h3>
+            <p className="text-xs text-muted-foreground">
+              {provider.providerType}
+            </p>
+          </div>
+        </div>
+
+        {/* 操作按钮 */}
+        <div className="flex items-center gap-1 opacity-0 transition-opacity group-hover:opacity-100">
+          <Button
+            variant="ghost"
+            size="icon"
+            className="h-8 w-8"
+            onClick={() => onSync(provider.id)}
+            title={t("universalProvider.sync", { defaultValue: "同步到应用" })}
+          >
+            <RefreshCw className="h-4 w-4" />
+          </Button>
+          <Button
+            variant="ghost"
+            size="icon"
+            className="h-8 w-8"
+            onClick={() => onEdit(provider)}
+            title={t("common.edit", { defaultValue: "编辑" })}
+          >
+            <Edit2 className="h-4 w-4" />
+          </Button>
+          <Button
+            variant="ghost"
+            size="icon"
+            className="h-8 w-8 text-destructive hover:text-destructive"
+            onClick={() => onDelete(provider.id)}
+            title={t("common.delete", { defaultValue: "删除" })}
+          >
+            <Trash2 className="h-4 w-4" />
+          </Button>
+        </div>
+      </div>
+
+      {/* 配置信息 */}
+      <div className="mt-4 space-y-2">
+        {/* Base URL */}
+        <div className="flex items-center gap-2 text-sm">
+          <Globe className="h-3.5 w-3.5 text-muted-foreground" />
+          <span className="truncate text-muted-foreground">
+            {provider.baseUrl || "-"}
+          </span>
+        </div>
+
+        {/* 启用的应用 */}
+        <div className="flex flex-wrap gap-1.5">
+          {enabledApps.map((app) => (
+            <span
+              key={app}
+              className="inline-flex items-center rounded-full bg-primary/10 px-2 py-0.5 text-xs font-medium text-primary"
+            >
+              {app}
+            </span>
+          ))}
+          {enabledApps.length === 0 && (
+            <span className="text-xs text-muted-foreground">
+              {t("universalProvider.noAppsEnabled", {
+                defaultValue: "未启用任何应用",
+              })}
+            </span>
+          )}
+        </div>
+      </div>
+
+      {/* 备注 */}
+      {provider.notes && (
+        <p className="mt-3 text-xs text-muted-foreground line-clamp-2">
+          {provider.notes}
+        </p>
+      )}
+    </div>
+  );
+}