Fix in-DB frontend serving its own index.html instead of the Oracle 26ai one

Moved index_indb.html into a dedicated frontend/indb/ subdirectory so the
in-DB backend (port 8002) serves the correct purple Oracle In-DB UI at /ui/.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

oravector-demo/backend/main_oracle_indb.py

@@ -10,7 +10,7 @@ load_dotenv()
 
 PHOTOS_DIR = os.getenv("PHOTOS_DIR")
 
-FRONTEND_DIR = os.path.join(os.path.dirname(__file__), "../../oravector-demo/frontend")
+FRONTEND_DIR = os.path.join(os.path.dirname(__file__), "../../oravector-demo/frontend/indb")
 
 app = FastAPI()
 app.add_middleware(CORSMiddleware, allow_origins=["*"], allow_methods=["*"], allow_headers=["*"])