feat: implemented the v1 browser embedded LLM support (Gemma 4 E4B based)

src/core/config-upgrader/KGConfigUpgrader.ts

@@ -1,6 +1,7 @@
 import { KGConfigStorage } from '../io/KGConfigStorage';
 import { CONFIG_UPGRADER_CONSTANTS } from '../../constants/coreConstants';
 import { upgradeConfigToV1 } from './upgradeConfigToV1';
+import { upgradeConfigToV2 } from './upgradeConfigToV2';
 
 /**
  * KGConfigUpgrader — Orchestrates app-level migrations (e.g., storage backend changes).
@@ -33,6 +34,10 @@ export class KGConfigUpgrader {
           await upgradeConfigToV1();
           break;
         }
+        case 2: {
+          await upgradeConfigToV2();
+          break;
+        }
         default: {
           throw new Error(`No config upgrader found for version ${nextVersion}`);
         }