Ensure website previews update instantly by disabling browser caching

Create a custom server script to serve files with explicit no-cache headers, resolving issues where the preview iframe displayed stale content due to browser caching.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: f5797e65-2210-4d2e-bf70-278d8a0098c1
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 2ef8619a-6329-44ec-aa16-6d651c828315
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/2a2c58da-54a0-4c86-8ad0-3b93439f70de/f5797e65-2210-4d2e-bf70-278d8a0098c1/D15BHvH
Replit-Helium-Checkpoint-Created: true

.replit

@@ -16,14 +16,14 @@ args = "Start application"
 name = "Start application"
 author = "agent"
 
-[[workflows.workflow.tasks]]
-task = "shell.exec"
-args = "python3 -m http.server 5000"
-waitForPort = 5000
-
 [workflows.workflow.metadata]
 outputType = "webview"
 
+[[workflows.workflow.tasks]]
+task = "shell.exec"
+args = "python3 serve.py"
+waitForPort = 5000
+
 [[ports]]
 localPort = 5000
 externalPort = 80

serve.py

@@ -0,0 +1,18 @@
+import http.server
+import socketserver
+
+PORT = 5000
+
+class NoCacheHandler(http.server.SimpleHTTPRequestHandler):
+    def end_headers(self):
+        self.send_header('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0')
+        self.send_header('Pragma', 'no-cache')
+        self.send_header('Expires', '0')
+        super().end_headers()
+
+class ReusableTCPServer(socketserver.TCPServer):
+    allow_reuse_address = True
+
+with ReusableTCPServer(("0.0.0.0", PORT), NoCacheHandler) as httpd:
+    print(f"Serving on port {PORT} with cache disabled")
+    httpd.serve_forever()