Feat default surface routing (#4)

Co-authored-by: Jeffrey Smith <jasafpro@gmail.com>
Co-committed-by: Jeffrey Smith <jasafpro@gmail.com>

src/js/sw/surfaces/admin/settings.js

@@ -7,21 +7,25 @@ const { useState, useEffect, useCallback } = hooks;
 export default function SettingsSection() {
     const [cfg, setCfg] = useState({});
     const [models, setModels] = useState([]);
+    const [surfaces, setSurfaces] = useState([]);
     const [vault, setVault] = useState(null);
     const [loading, setLoading] = useState(true);
     const [saving, setSaving] = useState(false);
 
     const load = useCallback(async () => {
         try {
-            const [s, m, v] = await Promise.all([
+            const [s, m, v, surfList] = await Promise.all([
                 sw.api.admin.settings.get(),
                 sw.api.admin.models.list().catch(() => []),
                 sw.api.admin.vault.status().catch(() => null),
+                sw.api.admin.surfaces.list().catch(() => []),
             ]);
             const raw = s || {};
             const pol = raw.policies || {};
             const cfg_ = raw.settings || {};
+            setSurfaces((surfList || []).filter(s => s.enabled));
             setCfg({
+                default_surface: cfg_.default_surface?.id || '',
                 allow_registration: pol.allow_registration === 'true',
                 registration_default_state: cfg_.registration_default_state || 'pending',
                 system_prompt: cfg_.system_prompt || '',
@@ -62,6 +66,9 @@ export default function SettingsSection() {
     async function save() {
         setSaving(true);
         try {
+            // Default surface
+            await sw.api.admin.settings.update('default_surface', { value: cfg.default_surface ? { id: cfg.default_surface } : null });
+
             // Policies
             await sw.api.admin.settings.update('allow_registration', { value: String(cfg.allow_registration) });
             await sw.api.admin.settings.update('registration_default_state', { value: cfg.registration_default_state });
@@ -128,6 +135,16 @@ export default function SettingsSection() {
 
     return html`
         <div class="admin-settings-form">
+            <div class="settings-section"><h3>Default Surface</h3>
+                <div class="form-group"><label>Landing page for /</label>
+                    <select value=${cfg.default_surface} onChange=${e => set('default_surface', e.target.value)}>
+                        <option value="">-- Auto (first extension surface, then Admin) --</option>
+                        ${surfaces.filter(s => s.source !== 'core').map(s => html`<option key=${s.id} value=${s.id}>${s.title || s.id}</option>`)}
+                    </select>
+                </div>
+                <span class="text-muted" style="font-size:12px;">Where users land when visiting /. Only extension surfaces are listed.</span>
+            </div>
+
             <div class="settings-section"><h3>Registration</h3>
                 <label class="toggle-label"><input type="checkbox" checked=${cfg.allow_registration} onChange=${e => set('allow_registration', e.target.checked)} /><span class="toggle-track"></span><span>Allow new user registration</span></label>
                 <div class="form-group" style="margin-top:8px;"><label>Default state</label>