ui: Refactor models store, MCP service, and gate logs behind VITE_DEBUG (#23236)

* refactor: Scope console logs to `DEV` + `VITE_DEBUG` env vars

* refactor: skip MCP proxy probe when no server requires it

* refactor: suppress expected disconnect errors during MCP client shutdown

* refactor: Deduplicate requests

* refactor: deduplicate model fetching across ROUTER and MODEL modes

* refactor: Clean up models logic

* chore: Add `.env.example` file

* refactor: replace client-side CORS proxy probe with server status flag

* refactor: Post-review fixes

* test: add vitest client setup with API fetch mocks

tools/ui/src/lib/utils/api-key-validation.ts

@@ -12,17 +12,21 @@ export async function validateApiKey(fetch: typeof globalThis.fetch): Promise<vo
 		return;
 	}
 
+	const apiKey = config().apiKey;
+
+	// No API key configured — server doesn't require auth, skip the request entirely.
+	// The /props endpoint is only protected when the server has API keys configured,
+	// and in that case the client always has one set (from settings).
+	if (!apiKey) {
+		return;
+	}
+
 	try {
-		const apiKey = config().apiKey;
-
 		const headers: Record<string, string> = {
-			'Content-Type': 'application/json'
+			'Content-Type': 'application/json',
+			Authorization: `Bearer ${apiKey}`
 		};
 
-		if (apiKey) {
-			headers.Authorization = `Bearer ${apiKey}`;
-		}
-
 		const response = await fetch(`${base}/props`, { headers });
 
 		if (!response.ok) {