fix: remove /api prefix from model-groups API calls (api.js already prepends it)

static/js/pages/model_groups.js

@@ -22,7 +22,7 @@ class ModelGroupsPage {
 
     async loadGroups() {
         try {
-            const groups = await api.get('/api/model-groups');
+            const groups = await api.get('/model-groups');
             const list = document.getElementById('model-groups-list');
             if (!groups || groups.length === 0) {
                 list.innerHTML = '<div class="empty-state">No model groups defined. Create one to enable auto-routing.</div>';
@@ -58,7 +58,7 @@ class ModelGroupsPage {
 
     async showEditForm(id) {
         try {
-            const groups = await api.get('/api/model-groups');
+            const groups = await api.get('/model-groups');
             const group = groups.find(g => g.id === id);
             if (group) this.renderForm(group);
         } catch (err) {
@@ -138,9 +138,9 @@ class ModelGroupsPage {
 
         try {
             if (isEdit) {
-                await api.put('/api/model-groups/' + encodeURIComponent(id), body);
+                await api.put('/model-groups/' + encodeURIComponent(id), body);
             } else {
-                await api.post('/api/model-groups', body);
+                await api.post('/model-groups', body);
             }
             document.getElementById('model-group-form').style.display = 'none';
             await this.loadGroups();
@@ -152,7 +152,7 @@ class ModelGroupsPage {
     async deleteGroup(id) {
         if (!confirm('Delete model group "' + id + '"? This cannot be undone.')) return;
         try {
-            await api.delete('/api/model-groups/' + encodeURIComponent(id));
+            await api.delete('/model-groups/' + encodeURIComponent(id));
             await this.loadGroups();
         } catch (err) {
             alert('Failed to delete: ' + err.message);