change image links from public to local

Apply endemecio02/node-red-contrib-httpauth#3 from @sakazuki

nodes/http-auth.html

@@ -71,7 +71,7 @@
 </p>
 
 <p>
-	<img src="https://raw.githubusercontent.com/alexandrainst/node-red-http-basic-auth/main/images/flow.png" />
+	<img src="node-red-http-basic-auth/images/flow.png" />
 <p>
 
 <h2>Config</h2>

nodes/http-auth.js

@@ -99,4 +99,25 @@ module.exports = function (RED) {
 	}
 
 	RED.nodes.registerType('http-basic-auth', HttpAuthNode);
+
+	if (RED.httpAdmin) {
+		const fs = require('fs');
+		const path = require('path');
+		RED.httpAdmin.get('/node-red-http-basic-auth/images/:file', function (req, res, next) {
+			const filename = req.params.file.replace(/[^a-zA-Z0-9._-]/g, '').replace(/^\.+/g, '');
+			fs.readFile(path.join(__dirname, '/../images/', filename), function (err, data) {
+				if (err) {
+					res.status(404).end();
+				} else {
+					res.set('Content-Type', 'image/png');
+					res.send(data, function (err) {
+						if (err) {
+							console.warn('Error serving image:', err);
+							res.status(500).end();
+						}
+					});
+				}
+			});
+		});
+	}
 };