fix(auth,services,profile): add request struct validation

Add validate tags and validators.Validate.Struct() calls on request structs for auth verification, service creation, and user patch test endpoints.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/handlers/services/services.go

@@ -88,6 +88,10 @@ func CreateServiceHandler(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "Invalid JSON: "+err.Error(), http.StatusBadRequest)
 		return
 	}
+	if err := validators.Validate.Struct(&req); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
 
 	// Basic validation
 	if req.Name == "" {