Keep the ai-chat model-map build inside the server lifecycle

onServerStart fired #buildModelMap without awaiting or tracking it, so
the network fetches it does (notably Ollama auto-discovery, which is
enabled by default and doomed on any machine without a local Ollama)
kept running after server.shutdown() resolved. In vitest that let the
provider's console.error land during worker teardown, which surfaces as
"Closing rpc while onUserConsoleLog was pending" — the unhandled error
that intermittently fails CI (last seen attributed to
WispController.test.ts). A rejection in the detached chain would also
have been an unhandled rejection.

Track the promise, catch and log rejections, and await it from
onServerShutdown so no provider I/O or logging outlives the server.
Also disable Ollama auto-discovery in setupTestServer's defaults —
every test server was firing a pointless model-list fetch at localhost.

src/backend/drivers/ai-chat/ChatCompletionDriver.ts

@@ -216,10 +216,22 @@ export class ChatCompletionDriver extends PuterDriver {
 
     #providers: Record<string, IChatProvider> = {};
     #modelIdMap: Record<string, IChatModel[]> = {};
+    #modelMapReady: Promise<void> = Promise.resolve();
 
     override onServerStart() {
         this.#registerProviders();
-        this.#buildModelMap();
+        // Not awaited — providers fetch model lists over the network and
+        // boot must not block on their latency. Shutdown awaits the
+        // tracked promise so provider I/O (and its error logging) never
+        // outlives the server; a rejection here must not become an
+        // unhandled one.
+        this.#modelMapReady = this.#buildModelMap().catch((e) => {
+            console.error('Failed to build ai-chat model map:', e);
+        });
+    }
+
+    override async onServerShutdown() {
+        await this.#modelMapReady;
     }
 
     // -- Interface methods -------------------------------------------

src/backend/testUtil.ts

@@ -153,6 +153,9 @@ export const setupTestServer = async (
             no_devwatch: true,
             no_browser_launch: true,
             import_ts_extensions: true,
+            // No local-Ollama auto-discovery: every test server would
+            // otherwise fire a doomed model-list fetch at localhost.
+            providers: { ollama: { enabled: false } },
         }),
         configOverrides ?? {},
     ) as IConfig;