feat(browser): add POST /open with session restore and reader mode

- restores cookies and localStorage from DB before page navigation
- readerMode flag extracts plain text via @mozilla/readability (Firefox reader engine)
- add localStorage default '{}' on session entity for clean schema migrations

src/app.module.ts

@@ -3,6 +3,7 @@ import { ConfigModule, ConfigService } from '@nestjs/config';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { HealthController } from './health/health.controller';
 import { AuthModule } from './auth/auth.module';
+import { BrowserModule } from './browser/browser.module';
 import { SessionEntity } from './session/session.entity';
 
 @Module({
@@ -21,6 +22,7 @@ import { SessionEntity } from './session/session.entity';
       }),
     }),
     AuthModule,
+    BrowserModule,
   ],
   controllers: [HealthController],
 })