allow overriding Core API URL

frontend/src/pages/Chat.tsx

@@ -436,7 +436,7 @@ const ChatPanel: FC = observer(() => {
     const chatSseController = new AbortController();
     chatSseControllers[answerId] = chatSseController;
     fetchEventSource( // https://api.openai.com/v1/chat/completions || http://127.0.0.1:${port}/v1/chat/completions
-      getServerRoot(port) + '/v1/chat/completions',
+      getServerRoot(port, true) + '/v1/chat/completions',
       {
         method: 'POST',
         headers: {

frontend/src/pages/Completion.tsx

@@ -82,7 +82,7 @@ const CompletionPanel: FC = observer(() => {
     let answer = '';
     completionSseController = new AbortController();
     fetchEventSource( // https://api.openai.com/v1/completions || http://127.0.0.1:${port}/v1/completions
-      getServerRoot(port) + '/v1/completions',
+      getServerRoot(port, true) + '/v1/completions',
       {
         method: 'POST',
         headers: {

frontend/src/pages/Composition.tsx

@@ -173,7 +173,7 @@ const CompositionPanel: FC = observer(() => {
     let answer = '';
     compositionSseController = new AbortController();
     fetchEventSource( // https://api.openai.com/v1/completions || http://127.0.0.1:${port}/v1/completions
-      getServerRoot(port) + '/v1/completions',
+      getServerRoot(port, true) + '/v1/completions',
       {
         method: 'POST',
         headers: {

frontend/src/pages/Settings.tsx

@@ -186,6 +186,16 @@ export const AdvancedGeneralSettings: FC = observer(() => {
           </Dropdown>
         </div>
       } />
+    <Labeled label={t('Core API URL')}
+      desc={t('Override core API URL(/chat/completions and /completions). If you don\'t know what this is, leave it blank.')}
+      content={
+        <Input style={{ minWidth: 0 }} className="grow" value={commonStore.settings.coreApiUrl}
+          onChange={(e, data) => {
+            commonStore.setSettings({
+              coreApiUrl: data.value
+            });
+          }} />
+      } />
   </div>;
 });