feat: implement Evodron Referral Program (backend, frontend, tests)

Co-authored-by: julesdemangeot-ship-it <307666271+julesdemangeot-ship-it@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+evodron.db
+*.db
+.env

app.js

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+'use strict';
+
+const express      = require('express');
+const cookieParser = require('cookie-parser');
+const path         = require('path');
+
+const authRoutes     = require('./src/routes/auth');
+const referralRoutes = require('./src/routes/referral');
+
+const app  = express();
+const PORT = process.env.PORT || 3000;
+
+// Middleware
+app.use(express.json());
+app.use(express.urlencoded({ extended: false }));
+app.use(cookieParser());
+
+// Serve static frontend files
+app.use(express.static(path.join(__dirname, 'public')));
+
+// API routes
+app.use('/api/auth',     authRoutes);
+app.use('/api/referral', referralRoutes);
+
+// Catch-all: serve index.html for client-side navigation
+app.get('*', (req, res) => {
+  res.sendFile(path.join(__dirname, 'public', 'index.html'));
+});
+
+// Only start listening when run directly (not during tests)
+if (require.main === module) {
+  if (!process.env.JWT_SECRET) {
+    console.error('ERROR: JWT_SECRET environment variable is not set. Refusing to start.');
+    process.exit(1);
+  }
+  app.listen(PORT, () => {
+    console.log(`Evodron Referral server running on http://localhost:${PORT}`);
+  });
+}
+
+module.exports = app;