refactor(utils): Extract utilities from server.js

- Create src/utils/http.js - fetchT and HTTP helpers
- Create src/utils/logging.js - Structured logging and error logging
- Create src/utils/responses.js - Standard API responses
- Create src/utils/async-handler.js - Async wrapper with error handling
- Create src/utils/index.js - Consolidated exports

Removes scattered helper functions from server.js

dashcaddy-api/src/utils/async-handler.js

@@ -0,0 +1,30 @@
+/**
+ * Async handler wrapper - Eliminates try/catch boilerplate
+ */
+const { AppError } = require('../../errors');
+
+/**
+ * Wrap async route handlers - catches errors and logs them
+ */
+function asyncHandler(logError, fn, context) {
+  return async (req, res, next) => {
+    try {
+      await fn(req, res, next);
+    } catch (error) {
+      // Let typed errors propagate to global error handler
+      if (error instanceof AppError) {
+        return next(error);
+      }
+      
+      await logError(context || req.path, error);
+      
+      if (!res.headersSent) {
+        const { errorResponse } = require('./responses');
+        const { safeErrorMessage } = require('./logging');
+        errorResponse(res, 500, safeErrorMessage(error));
+      }
+    }
+  };
+}
+
+module.exports = { asyncHandler };