feat(core,ui): support Gemini 3.1 Pro Preview and active model filtering (#125)

* feat(core,ui): support Gemini 3.1 Pro Preview and active model filtering

* fix(core,ui): use optional chaining for config methods to support mocks

* fix(core): clear stale authType in refreshAuth to avoid incorrect model resolution

* do not show gemini 3.1 model when users do not have access to gemini 3.1 in stats

packages/cli/src/zed-integration/zedIntegration.ts

@@ -483,7 +483,10 @@ export class Session {
       const functionCalls: FunctionCall[] = [];
 
       try {
-        const model = resolveModel(this.config.getModel());
+        const model = resolveModel(
+          this.config.getModel(),
+          (await this.config.getGemini31Launched?.()) ?? false,
+        );
         const responseStream = await chat.sendMessageStream(
           { model },
           nextMessage?.parts ?? [],