docling separation

docs/content/Deploying/Development-Environment.mdx

@@ -96,6 +96,13 @@ To run the DocsGPT backend locally, you'll need to set up a Python environment a
     pip install -r application/requirements.txt
     ```
 
+    Optionally add the docling parser engine (OCR, `structured` output for
+    `read_document`; the default anydoc engine does not need it):
+
+    ```bash
+    pip install -r application/requirements-docling.txt
+    ```
+
 5.  **Run the Backend:**
 
     For local development, run the ASGI composition under uvicorn. It serves the **whole** application, hot-reloads on source changes, and matches the production runtime:

docs/content/Deploying/DocsGPT-Settings.mdx

@@ -206,7 +206,7 @@ for the engines and flows.
 
 | Setting | Default | Description |
 | --- | --- | --- |
-| `DOC_PARSER_ENGINE` | `anydoc` | Parser engine: `anydoc` (fast Rust converter, no ML models) or `docling` (layout/table models, OCR, structured output; heavy optional install). Files anydoc cannot read fall back to Docling when installed. |
+| `DOC_PARSER_ENGINE` | `anydoc` | Parser engine: `anydoc` (fast Rust converter, no ML models) or `docling` (layout/table models, OCR, structured output). Files anydoc cannot read fall back to Docling when installed. Docling is an optional extra: `pip install -r application/requirements-docling.txt`, or Docker builds with `--build-arg INSTALL_DOCLING=true`. |
 | `DOCLING_OCR_ENABLED` | `false` | OCR for source ingestion (Docling only). |
 | `DOCLING_OCR_ATTACHMENTS_ENABLED` | `false` | OCR for chat attachments (Docling only). |
 | `ATTACHMENT_PDF_TEXT_FAST_PATH` | `true` | Under the `docling` engine, read PDF attachments through their text layer (pypdfium2) and only hand scans to Docling. Not needed under `anydoc`. |