feat: enhance evobgp with new command-line tools for bundle management, including pull, verify, and apply functionalities. Update go.mod to include necessary dependencies and complete todos in architecture plan for improved observability and deployment practices.

internal/httpapi/problem.go

@@ -0,0 +1,36 @@
+package httpapi
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+// Problem is RFC 9457 application/problem+json.
+type Problem struct {
+	Type     string         `json:"type,omitempty"`
+	Title    string         `json:"title"`
+	Status   int            `json:"status"`
+	Detail   string         `json:"detail,omitempty"`
+	Instance string         `json:"instance,omitempty"`
+}
+
+func writeProblem(w http.ResponseWriter, status int, title, detail string) {
+	w.Header().Set("Content-Type", "application/problem+json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(Problem{
+		Type:   "about:blank",
+		Title:  title,
+		Status: status,
+		Detail: detail,
+	})
+}
+
+func writeJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+func writeNoContent(w http.ResponseWriter) {
+	w.WriteHeader(http.StatusNoContent)
+}