feat: add PaddleOCR-vl loader support and implement retrieval router infrastructure (#23945)

Co-authored-by: Tim Baek <tim@openwebui.com>
Co-authored-by: joaoback <156559121+joaoback@users.noreply.github.com>

backend/open_webui/retrieval/utils.py

@@ -114,6 +114,8 @@ def build_loader_from_config(request):
         DOCUMENT_INTELLIGENCE_MODEL=config.DOCUMENT_INTELLIGENCE_MODEL,
         MISTRAL_OCR_API_BASE_URL=config.MISTRAL_OCR_API_BASE_URL,
         MISTRAL_OCR_API_KEY=config.MISTRAL_OCR_API_KEY,
+        PADDLEOCR_VL_BASE_URL=config.PADDLEOCR_VL_BASE_URL,
+        PADDLEOCR_VL_TOKEN=config.PADDLEOCR_VL_TOKEN,
         MINERU_API_MODE=config.MINERU_API_MODE,
         MINERU_API_URL=config.MINERU_API_URL,
         MINERU_API_KEY=config.MINERU_API_KEY,