fix: use backend:8000 for container network in wizard default

src/pages/SetupWizardPage.tsx

@@ -38,7 +38,7 @@ export default function SetupWizardPage({ wizardBase, onComplete }: Props) {
     db_user: 'harborforge',
     db_password: 'harborforge_pass',
     db_database: 'harborforge',
-    backend_base_url: 'http://127.0.0.1:8000',
+    backend_base_url: 'http://backend:8000',
     project_name: '',
     project_description: '',
   })
@@ -182,7 +182,7 @@ export default function SetupWizardPage({ wizardBase, onComplete }: Props) {
             <h2>Backend URL</h2>
             <p className="text-dim">Configure the HarborForge backend API URL</p>
             <div className="setup-form">
-              <label>Backend Base URL <input value={form.backend_base_url} onChange={(e) => set('backend_base_url', e.target.value)} placeholder="http://127.0.0.1:8000" /></label>
+              <label>Backend Base URL <input value={form.backend_base_url} onChange={(e) => set('backend_base_url', e.target.value)} placeholder="http://backend:8000" /></label>
             </div>
             <div className="setup-nav">
               <button className="btn-back" onClick={() => setStep(2)}>Back</button>