Perplexity API key validation uses deprecated /models endpoint

[gaoliao1688]

Summary

In v0.5.4, valid Perplexity API keys can be marked as invalid because provider validation and model listing still call:

https://api.perplexity.ai/models

That endpoint now returns 404. Perplexity's current API reference uses:

https://api.perplexity.ai/v1/models

The Search API endpoint itself still works at https://api.perplexity.ai/search, so this is specifically a validation/model-list endpoint issue.

Impact

A valid pplx-... API key may fail validation with Invalid API key, causing the perplexity provider connection to stay disabled. As a result, /v1/search with provider perplexity cannot be used until the connection is manually re-enabled or the endpoint is patched.

Verification

Tested from a server running 9router@0.5.4 with a valid Perplexity API key. Secret omitted.

GET  https://api.perplexity.ai/models      -> 404
GET  https://api.perplexity.ai/v1/models   -> 200
POST https://api.perplexity.ai/search      -> 200

After changing the validation/model endpoints to /v1/models, the local 9router endpoint succeeds:

POST /v1/search provider=perplexity -> 200

Minimal patch

diff --git a/src/app/api/providers/validate/route.js b/src/app/api/providers/validate/route.js
--- a/src/app/api/providers/validate/route.js
+++ b/src/app/api/providers/validate/route.js
@@
-            perplexity: "https://api.perplexity.ai/models",
+            perplexity: "https://api.perplexity.ai/v1/models",

diff --git a/src/app/api/providers/[id]/test/testUtils.js b/src/app/api/providers/[id]/test/testUtils.js
--- a/src/app/api/providers/[id]/test/testUtils.js
+++ b/src/app/api/providers/[id]/test/testUtils.js
@@
-        const res = await fetchWithConnectionProxy("https://api.perplexity.ai/models", { headers: { Authorization: `Bearer ${connection.apiKey}` } }, effectiveProxy);
+        const res = await fetchWithConnectionProxy("https://api.perplexity.ai/v1/models", { headers: { Authorization: `Bearer ${connection.apiKey}` } }, effectiveProxy);

diff --git a/src/app/api/providers/[id]/models/route.js b/src/app/api/providers/[id]/models/route.js
--- a/src/app/api/providers/[id]/models/route.js
+++ b/src/app/api/providers/[id]/models/route.js
@@
-  perplexity: createOpenAIModelsConfig("https://api.perplexity.ai/models"),
+  perplexity: createOpenAIModelsConfig("https://api.perplexity.ai/v1/models"),

Notes

This does not change the Perplexity Search API config, which already points to https://api.perplexity.ai/search. It only updates provider validation and model listing to the current models endpoint.