feat(core): enable getUserTierName in config (#18265)

packages/core/src/config/config.test.ts

@@ -2087,8 +2087,7 @@ describe('Config Quota & Preview Model Access', () => {
       await config.refreshAuth(AuthType.USE_GEMINI);
 
       expect(config.getUserTier()).toBe(mockTier);
-      // TODO(#1275): User tier name is disabled until re-enabled.
-      expect(config.getUserTierName()).toBeUndefined();
+      expect(config.getUserTierName()).toBe(mockTierName);
     });
   });
 

packages/core/src/config/config.ts

@@ -1047,8 +1047,7 @@ export class Config {
   }
 
   getUserTierName(): string | undefined {
-    // TODO(#1275): Re-enable user tier display when ready.
-    return undefined;
+    return this.contentGenerator?.userTierName;
   }
 
   /**