hscontrol, cli: add auth register and approve commands

Implement AuthRegister and AuthApprove gRPC handlers and add
corresponding CLI commands (headscale auth register, approve, reject)
for managing pending auth requests including SSH check approvals.

Updates #1850

hscontrol/handlers.go

@@ -282,7 +282,7 @@ func (a *AuthProviderWeb) AuthHandler(
 }
 
 func authIDFromRequest(req *http.Request) (types.AuthID, error) {
-	registrationId, err := urlParam[types.AuthID](req, "auth_id")
+	raw, err := urlParam[string](req, "auth_id")
 	if err != nil {
 		return "", NewHTTPError(http.StatusBadRequest, "invalid registration id", fmt.Errorf("parsing auth_id from URL: %w", err))
 	}
@@ -290,7 +290,7 @@ func authIDFromRequest(req *http.Request) (types.AuthID, error) {
 	// We need to make sure we dont open for XSS style injections, if the parameter that
 	// is passed as a key is not parsable/validated as a NodePublic key, then fail to render
 	// the template and log an error.
-	err = registrationId.Validate()
+	registrationId, err := types.AuthIDFromString(raw)
 	if err != nil {
 		return "", NewHTTPError(http.StatusBadRequest, "invalid registration id", fmt.Errorf("parsing auth_id from URL: %w", err))
 	}