feat: add provider user agent override

src/components/providers/forms/ProviderForm.tsx

@@ -355,6 +355,7 @@ function ProviderFormFull({
       ),
     });
     setCodexChatReasoning(initialData?.meta?.codexChatReasoning ?? {});
+    setCustomUserAgent(initialData?.meta?.customUserAgent ?? "");
   }, [appId, initialData, supportsFullUrl]);
 
   const defaultValues: ProviderFormData = useMemo(
@@ -509,6 +510,9 @@ function ProviderFormFull({
     useState<CodexChatReasoning>(
       () => initialData?.meta?.codexChatReasoning ?? {},
     );
+  const [customUserAgent, setCustomUserAgent] = useState<string>(
+    () => initialData?.meta?.customUserAgent ?? "",
+  );
 
   const {
     codexAuth,
@@ -1386,6 +1390,10 @@ function ProviderFormFull({
         localCodexApiFormat === "openai_chat"
           ? normalizeCodexChatReasoningForSave(codexChatReasoning)
           : undefined,
+      customUserAgent:
+        appId === "claude" || appId === "codex"
+          ? customUserAgent.trim() || undefined
+          : undefined,
       testConfig: testConfig.enabled ? testConfig : undefined,
       costMultiplier: pricingConfig.enabled
         ? pricingConfig.costMultiplier
@@ -2009,6 +2017,8 @@ function ProviderFormFull({
               onApiKeyFieldChange={handleApiKeyFieldChange}
               isFullUrl={localIsFullUrl}
               onFullUrlChange={setLocalIsFullUrl}
+              customUserAgent={customUserAgent}
+              onCustomUserAgentChange={setCustomUserAgent}
             />
           )}
 
@@ -2041,6 +2051,8 @@ function ProviderFormFull({
               catalogModels={codexCatalogModels}
               onCatalogModelsChange={setCodexCatalogModels}
               speedTestEndpoints={speedTestEndpoints}
+              customUserAgent={customUserAgent}
+              onCustomUserAgentChange={setCustomUserAgent}
             />
           )}