feat: differentiate fetch models error messages by failure type

Distinguish between missing API key, missing endpoint, auth failure,
unsupported provider (404/405), and timeout errors instead of showing
a generic failure toast for all cases.

src/components/providers/forms/ClaudeFormFields.tsx

@@ -33,7 +33,11 @@ import {
   copilotGetModelsForAccount,
 } from "@/lib/api/copilot";
 import type { CopilotModel } from "@/lib/api/copilot";
-import { fetchModelsForConfig, type FetchedModel } from "@/lib/api/model-fetch";
+import {
+  fetchModelsForConfig,
+  showFetchModelsError,
+  type FetchedModel,
+} from "@/lib/api/model-fetch";
 import type {
   ProviderCategory,
   ClaudeApiFormat,
@@ -186,7 +190,10 @@ export function ClaudeFormFields({
 
   const handleFetchModels = useCallback(() => {
     if (!baseUrl || !apiKey) {
-      toast.error(t("providerForm.fetchModelsFailed"));
+      showFetchModelsError(null, t, {
+        hasApiKey: !!apiKey,
+        hasBaseUrl: !!baseUrl,
+      });
       return;
     }
     setIsFetchingModels(true);
@@ -203,7 +210,7 @@ export function ClaudeFormFields({
       })
       .catch((err) => {
         console.warn("[ModelFetch] Failed:", err);
-        toast.error(t("providerForm.fetchModelsFailed"));
+        showFetchModelsError(err, t);
       })
       .finally(() => setIsFetchingModels(false));
   }, [baseUrl, apiKey, isFullUrl, t]);

src/components/providers/forms/CodexFormFields.tsx

@@ -5,7 +5,11 @@ import { toast } from "sonner";
 import { Download, Loader2 } from "lucide-react";
 import EndpointSpeedTest from "./EndpointSpeedTest";
 import { ApiKeySection, EndpointField, ModelInputWithFetch } from "./shared";
-import { fetchModelsForConfig, type FetchedModel } from "@/lib/api/model-fetch";
+import {
+  fetchModelsForConfig,
+  showFetchModelsError,
+  type FetchedModel,
+} from "@/lib/api/model-fetch";
 import type { ProviderCategory } from "@/types";
 
 interface EndpointCandidate {
@@ -75,7 +79,10 @@ export function CodexFormFields({
 
   const handleFetchModels = useCallback(() => {
     if (!codexBaseUrl || !codexApiKey) {
-      toast.error(t("providerForm.fetchModelsFailed"));
+      showFetchModelsError(null, t, {
+        hasApiKey: !!codexApiKey,
+        hasBaseUrl: !!codexBaseUrl,
+      });
       return;
     }
     setIsFetchingModels(true);
@@ -92,7 +99,7 @@ export function CodexFormFields({
       })
       .catch((err) => {
         console.warn("[ModelFetch] Failed:", err);
-        toast.error(t("providerForm.fetchModelsFailed"));
+        showFetchModelsError(err, t);
       })
       .finally(() => setIsFetchingModels(false));
   }, [codexBaseUrl, codexApiKey, isFullUrl, t]);

src/components/providers/forms/GeminiFormFields.tsx

@@ -6,7 +6,11 @@ import { Button } from "@/components/ui/button";
 import { toast } from "sonner";
 import EndpointSpeedTest from "./EndpointSpeedTest";
 import { ApiKeySection, EndpointField, ModelInputWithFetch } from "./shared";
-import { fetchModelsForConfig, type FetchedModel } from "@/lib/api/model-fetch";
+import {
+  fetchModelsForConfig,
+  showFetchModelsError,
+  type FetchedModel,
+} from "@/lib/api/model-fetch";
 import type { ProviderCategory } from "@/types";
 
 interface EndpointCandidate {
@@ -74,7 +78,10 @@ export function GeminiFormFields({
 
   const handleFetchModels = useCallback(() => {
     if (!baseUrl || !apiKey) {
-      toast.error(t("providerForm.fetchModelsFailed"));
+      showFetchModelsError(null, t, {
+        hasApiKey: !!apiKey,
+        hasBaseUrl: !!baseUrl,
+      });
       return;
     }
     setIsFetchingModels(true);
@@ -91,7 +98,7 @@ export function GeminiFormFields({
       })
       .catch((err) => {
         console.warn("[ModelFetch] Failed:", err);
-        toast.error(t("providerForm.fetchModelsFailed"));
+        showFetchModelsError(err, t);
       })
       .finally(() => setIsFetchingModels(false));
   }, [baseUrl, apiKey, t]);

src/components/providers/forms/OpenClawFormFields.tsx

@@ -35,7 +35,11 @@ import {
 } from "@/components/ui/dropdown-menu";
 import { Checkbox } from "@/components/ui/checkbox";
 import { ApiKeySection } from "./shared";
-import { fetchModelsForConfig, type FetchedModel } from "@/lib/api/model-fetch";
+import {
+  fetchModelsForConfig,
+  showFetchModelsError,
+  type FetchedModel,
+} from "@/lib/api/model-fetch";
 import { openclawApiProtocols } from "@/config/openclawProviderPresets";
 import type { ProviderCategory, OpenClawModel } from "@/types";
 
@@ -129,7 +133,10 @@ export function OpenClawFormFields({
   // Fetch models from API
   const handleFetchModels = useCallback(() => {
     if (!baseUrl || !apiKey) {
-      toast.error(t("providerForm.fetchModelsFailed"));
+      showFetchModelsError(null, t, {
+        hasApiKey: !!apiKey,
+        hasBaseUrl: !!baseUrl,
+      });
       return;
     }
     setIsFetchingModels(true);
@@ -146,7 +153,7 @@ export function OpenClawFormFields({
       })
       .catch((err) => {
         console.warn("[ModelFetch] Failed:", err);
-        toast.error(t("providerForm.fetchModelsFailed"));
+        showFetchModelsError(err, t);
       })
       .finally(() => setIsFetchingModels(false));
   }, [baseUrl, apiKey, t]);

src/components/providers/forms/OpenCodeFormFields.tsx

@@ -28,7 +28,11 @@ import {
   DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
 import { ApiKeySection } from "./shared";
-import { fetchModelsForConfig, type FetchedModel } from "@/lib/api/model-fetch";
+import {
+  fetchModelsForConfig,
+  showFetchModelsError,
+  type FetchedModel,
+} from "@/lib/api/model-fetch";
 import { opencodeNpmPackages } from "@/config/opencodeProviderPresets";
 import { cn } from "@/lib/utils";
 import {
@@ -247,7 +251,10 @@ export function OpenCodeFormFields({
 
   const handleFetchModels = useCallback(() => {
     if (!baseUrl || !apiKey) {
-      toast.error(t("providerForm.fetchModelsFailed"));
+      showFetchModelsError(null, t, {
+        hasApiKey: !!apiKey,
+        hasBaseUrl: !!baseUrl,
+      });
       return;
     }
     setIsFetchingModels(true);
@@ -264,7 +271,7 @@ export function OpenCodeFormFields({
       })
       .catch((err) => {
         console.warn("[ModelFetch] Failed:", err);
-        toast.error(t("providerForm.fetchModelsFailed"));
+        showFetchModelsError(err, t);
       })
       .finally(() => setIsFetchingModels(false));
   }, [baseUrl, apiKey, t]);