Add vLLM v0.18.1 source tree with KV transfer abort fix

third_party/vllm/ now tracked in git for direct patch management.
Based on vLLM v0.18.1 release with one patch applied:

  vllm/v1/core/sched/scheduler.py:
    Replace fatal assert with graceful skip when KV transfer callback
    arrives for an already-aborted request during PD disaggregated serving.

Future vLLM modifications should be made directly in third_party/vllm/
and committed normally. The patches/ directory is kept as documentation
of what changed from upstream.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

third_party/vllm/docs/deployment/frameworks/anything-llm.md

@@ -0,0 +1,53 @@
+# AnythingLLM
+
+[AnythingLLM](https://github.com/Mintplex-Labs/anything-llm) is a full-stack application that enables you to turn any document, resource, or piece of content into context that any LLM can use as references during chatting.
+
+It allows you to deploy a large language model (LLM) server with vLLM as the backend, which exposes OpenAI-compatible endpoints.
+
+## Prerequisites
+
+Set up the vLLM environment:
+
+```bash
+pip install vllm
+```
+
+## Deploy
+
+1. Start the vLLM server with a supported chat-completion model, for example:
+
+    ```bash
+    vllm serve Qwen/Qwen1.5-32B-Chat-AWQ --max-model-len 4096
+    ```
+
+1. Download and install [AnythingLLM Desktop](https://anythingllm.com/desktop).
+
+1. Configure the AI provider:
+
+    - At the bottom, click the 🔧 wrench icon -> **Open settings** -> **AI Providers** -> **LLM**.
+    - Enter the following values:
+        - LLM Provider: Generic OpenAI
+        - Base URL: `http://{vllm server host}:{vllm server port}/v1`
+        - Chat Model Name: `Qwen/Qwen1.5-32B-Chat-AWQ`
+
+    ![set AI providers](../../assets/deployment/anything-llm-provider.png)
+
+1. Create a workspace:
+
+    1. At the bottom, click the ↺ back icon and back to workspaces.
+    1. Create a workspace (e.g., `vllm`) and start chatting.
+
+    ![create a workspace](../../assets/deployment/anything-llm-chat-without-doc.png)
+
+1. Add a document.
+
+    1. Click the 📎 attachment icon.
+    1. Upload a document.
+    1. Select and move the document into your workspace.
+    1. Save and embed it.
+
+    ![add a document](../../assets/deployment/anything-llm-upload-doc.png)
+
+1. Chat using your document as context.
+
+    ![chat with your context](../../assets/deployment/anything-llm-chat-with-doc.png)