feat: add MCP server testing and tool listing functionality

- Add MCPTestService for testing MCP server connections
- Support stdio, SSE, and HTTP transport types
- Implement workaround for SSE headers bug (SDK Issue #436)
- Create API routes for /api/mcp/test and /api/mcp/tools
- Add API client methods for MCP operations
- Create MCPToolsList component with collapsible schema display
- Add Test button to MCP servers section with status indicators
- Add Headers field for HTTP/SSE servers
- Add Environment Variables field for stdio servers
- Fix text overflow in tools list display

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/server/src/routes/mcp/common.ts

@@ -0,0 +1,20 @@
+/**
+ * Common utilities for MCP routes
+ */
+
+/**
+ * Extract error message from unknown error
+ */
+export function getErrorMessage(error: unknown): string {
+  if (error instanceof Error) {
+    return error.message;
+  }
+  return String(error);
+}
+
+/**
+ * Log error with prefix
+ */
+export function logError(error: unknown, message: string): void {
+  console.error(`[MCP] ${message}:`, error);
+}