oss(py): add ChatLiteLLM to chat index, update feature flags (#2997)

Add `ChatLiteLLM` to the chat integrations index and update its feature
matrix to reflect newly supported capabilities (structured output and
image input).

## Changes
- Add `ChatLiteLLM` to the main chat models table and the "Routers &
proxies" section in `chat/index.mdx`
- Mark structured output and image input as supported (❌ → ✅) in the
`ChatLiteLLM` model features table

Author: mdrxy

src/oss/python/integrations/chat/index.mdx

@@ -37,6 +37,7 @@ description: "Integrate with chat models using LangChain Python."
 | [`ChatDatabricks`](/oss/integrations/chat/databricks) | ✅ | ✅ | ❌ |
 | [`ChatPerplexity`](/oss/integrations/chat/perplexity) | ❌ | ✅ | ✅ |
 | [`ChatOpenRouter`](/oss/integrations/chat/openrouter) | ✅ | ✅ | ✅ |
+| [`ChatLiteLLM`](/oss/integrations/chat/litellm) | ✅ | ✅ | ✅ |
 
 ### Routers & proxies
 
@@ -45,6 +46,7 @@ Routers and proxies give you access to models from multiple providers through a
 | Provider | Integration | Description |
 |-|-|-|
 | [OpenRouter](https://openrouter.ai/) | [`ChatOpenRouter`](/oss/integrations/chat/openrouter) | Unified access to models from OpenAI, Anthropic, Google, Meta, and more |
+| [LiteLLM](https://www.litellm.ai/) | [`ChatLiteLLM`](/oss/integrations/chat/litellm) | Unified interface for OpenAI, Anthropic, Azure, Hugging Face, and more with routing and fallbacks |
 
 ## Chat Completions API
 

src/oss/python/integrations/chat/litellm.mdx

@@ -18,14 +18,14 @@ This integration contains two main classes:
 
 | Class | Package | Serializable | JS support| Downloads | Version |
 | :---  | :--- | :---: |  :---: | :---: | :---: |
-| [`ChatLiteLLM`](/oss/integrations/chat/litellm) | [`langchain-litellm`](https://pypi.org/project/langchain-litellm/)| ❌ | ❌ | ![PyPI - Downloads](https://img.shields.io/pypi/dm/langchain-litellm?style=flat-square&label=%20) | ![PyPI - Version](https://img.shields.io/pypi/v/langchain-litellm?style=flat-square&label=%20) |
-| [`ChatLiteLLMRouter`](/oss/integrations/chat/litellm) | [`langchain-litellm`](https://pypi.org/project/langchain-litellm/)| ❌ | ❌ | ![PyPI - Downloads](https://img.shields.io/pypi/dm/langchain-litellm?style=flat-square&label=%20) | ![PyPI - Version](https://img.shields.io/pypi/v/langchain-litellm?style=flat-square&label=%20) |
+| [`ChatLiteLLM`](https://reference.langchain.com/python/langchain-litellm/chat_models/litellm/ChatLiteLLM) | [`langchain-litellm`](https://pypi.org/project/langchain-litellm/)| ❌ | ❌ | ![PyPI - Downloads](https://img.shields.io/pypi/dm/langchain-litellm?style=flat-square&label=%20) | ![PyPI - Version](https://img.shields.io/pypi/v/langchain-litellm?style=flat-square&label=%20) |
+| [`ChatLiteLLMRouter`](https://reference.langchain.com/python/langchain-litellm/chat_models/litellm_router/ChatLiteLLMRouter) | [`langchain-litellm`](https://pypi.org/project/langchain-litellm/)| ❌ | ❌ | ![PyPI - Downloads](https://img.shields.io/pypi/dm/langchain-litellm?style=flat-square&label=%20) | ![PyPI - Version](https://img.shields.io/pypi/v/langchain-litellm?style=flat-square&label=%20) |
 
 ### Model features
 
 | [Tool calling](/oss/langchain/tools) | [Structured output](/oss/langchain/structured-output#structured-output) | Image input | Audio input | Video input | [Token-level streaming](/oss/integrations/chat/litellm#async-and-streaming-functionality) | [Native async](/oss/integrations/chat/litellm#async-and-streaming-functionalityy) | [Token usage](/oss/langchain/models#token-usage) | [Logprobs](/oss/langchain/models#log-probabilities) |
 | :---: | :---: | :---: |  :---: | :---: | :---: | :---: | :---: | :---: |
-| ✅ | ❌ | ❌ | ❌ | ❌ | ✅ | ✅ | ✅ | ❌ |
+| ✅ | ✅ | ✅ | ❌ | ❌ | ✅ | ✅ | ✅ | ❌ |
 
 ### Setup
 
@@ -139,4 +139,4 @@ It is important to note that antibiotics only work against bacterial infections
 
 ## API reference
 
-For detailed documentation of all `ChatLiteLLM` and `ChatLiteLLMRouter` features and configurations, head to the API reference: [github.com/langchain-ai/langchain-litellm](https://github.com/langchain-ai/langchain-litellm)
+For detailed documentation of all `ChatLiteLLM` and `ChatLiteLLMRouter` features and configurations, head to the [API reference](https://reference.langchain.com/python/langchain-litellm).

src/oss/python/integrations/providers/litellm.mdx

@@ -29,4 +29,4 @@ See more detail in the guide [here](/oss/integrations/chat/litellm).
 ---
 
 ## API reference
-For detailed documentation of all `ChatLiteLLM` and `ChatLiteLLMRouter` features and configurations head to the API reference: https://github.com/Akshay-Dongare/langchain-litellm
+For detailed documentation of all `ChatLiteLLM` and `ChatLiteLLMRouter` features and configurations head to the [API reference](https://reference.langchain.com/python/langchain-litellm).