feat: add TLS certificate management functionality

- Implemented TLS certificate model and service for managing certificates.
- Added API endpoints for creating, importing, listing, and deleting TLS certificates.
- Enhanced proxy route configuration to support HTTPS with certificate selection.
- Updated frontend to include TLS certificate management UI with manual and file import options.
- Added validation for HTTPS routes to ensure certificates are selected.
- Implemented tests for TLS certificate creation and proxy route validation.

atsf_server/model/tls_certificate.go

@@ -0,0 +1,34 @@
+package model
+
+import "time"
+
+type TLSCertificate struct {
+	ID        uint      `json:"id" gorm:"primaryKey"`
+	Name      string    `json:"name" gorm:"uniqueIndex;size:255;not null"`
+	CertPEM   string    `json:"cert_pem" gorm:"type:text;not null"`
+	KeyPEM    string    `json:"key_pem" gorm:"type:text;not null"`
+	NotBefore time.Time `json:"not_before"`
+	NotAfter  time.Time `json:"not_after"`
+	Remark    string    `json:"remark" gorm:"size:255"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+func ListTLSCertificates() (certificates []*TLSCertificate, err error) {
+	err = DB.Order("id desc").Find(&certificates).Error
+	return certificates, err
+}
+
+func GetTLSCertificateByID(id uint) (*TLSCertificate, error) {
+	certificate := &TLSCertificate{}
+	err := DB.First(certificate, id).Error
+	return certificate, err
+}
+
+func (certificate *TLSCertificate) Insert() error {
+	return DB.Create(certificate).Error
+}
+
+func (certificate *TLSCertificate) Delete() error {
+	return DB.Delete(certificate).Error
+}