feat: add provider-specific terminal button

Add a terminal button next to each provider card that opens a new terminal
window with that provider's specific API configuration. This allows using
different providers independently without changing the global setting.

Changes:
- Backend: Add `open_provider_terminal` command that extracts provider
  config and creates a temporary claude settings file
- Frontend: Add terminal button to provider cards with proper callback
  propagation through component hierarchy
- Support macOS (Terminal.app), Linux (gnome-terminal, konsole, etc.),
  and Windows (cmd)

Each provider gets a unique config file named `claude_<providerId>_<pid>.json`
in the temp directory, containing the provider's API configuration.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/components/providers/ProviderList.tsx

@@ -41,6 +41,7 @@ interface ProviderListProps {
   onDuplicate: (provider: Provider) => void;
   onConfigureUsage?: (provider: Provider) => void;
   onOpenWebsite: (url: string) => void;
+  onOpenTerminal?: (provider: Provider) => void;
   onCreate?: () => void;
   isLoading?: boolean;
   isProxyRunning?: boolean; // 代理服务运行状态
@@ -58,6 +59,7 @@ export function ProviderList({
   onDuplicate,
   onConfigureUsage,
   onOpenWebsite,
+  onOpenTerminal,
   onCreate,
   isLoading = false,
   isProxyRunning = false,
@@ -203,6 +205,7 @@ export function ProviderList({
               onDuplicate={onDuplicate}
               onConfigureUsage={onConfigureUsage}
               onOpenWebsite={onOpenWebsite}
+              onOpenTerminal={onOpenTerminal}
               onTest={handleTest}
               isTesting={isChecking(provider.id)}
               isProxyRunning={isProxyRunning}
@@ -311,6 +314,7 @@ interface SortableProviderCardProps {
   onDuplicate: (provider: Provider) => void;
   onConfigureUsage?: (provider: Provider) => void;
   onOpenWebsite: (url: string) => void;
+  onOpenTerminal?: (provider: Provider) => void;
   onTest: (provider: Provider) => void;
   isTesting: boolean;
   isProxyRunning: boolean;
@@ -333,6 +337,7 @@ function SortableProviderCard({
   onDuplicate,
   onConfigureUsage,
   onOpenWebsite,
+  onOpenTerminal,
   onTest,
   isTesting,
   isProxyRunning,
@@ -371,6 +376,7 @@ function SortableProviderCard({
           onConfigureUsage ? (item) => onConfigureUsage(item) : () => undefined
         }
         onOpenWebsite={onOpenWebsite}
+        onOpenTerminal={onOpenTerminal}
         onTest={onTest}
         isTesting={isTesting}
         isProxyRunning={isProxyRunning}