Add support for OpenAI built-in tools (web_search, code_interpreter)

Document the new tools feature in README, features.md, and providers.md.
Update the `!bai providers` command output to show vision/tools support
consistently for all providers.

Based on #62 by @yeslayla which migrated the OpenAI provider to the
Responses API.

See: https://github.com/etkecc/baibot/pull/62

docs/features.md

@@ -40,6 +40,23 @@ You may also wish to see:
 - [📖 Usage / 💬 Text Generation](./usage.md#-text-generation) section for more details on how to use the bot for Text Generation in a room
 
 
+#### 🛠️ Built-in Tools (OpenAI only)
+
+
+
+The [OpenAI provider](./providers.md#openai) supports built-in tools that extend the model's capabilities:
+
+- [🔍 Web Search](https://platform.openai.com/docs/guides/tools-web-search) (`web_search`): allows the model to search the web for up-to-date information. [🖼️ Screenshot](./screenshots/text-generation-tools-web-search.webp)
+
+- [💻 Code Interpreter](https://platform.openai.com/docs/guides/tools-code-interpreter) (`code_interpreter`): allows the model to write and execute Python code in a sandbox
+
+These tools are **disabled by default** and need to be explicitly enabled in the agent's `text_generation.tools` configuration. See the [OpenAI sample configuration](https://github.com/etkecc/baibot/blob/c70387b0c38d8d0f30bba2179a2a21a3710dbeaf/docs/sample-provider-configs/openai.yml#L12-L15) for reference.
+
+To enable tools on an existing dynamically-created agent, you need to [update the agent](./agents.md#updating-agents) to re-create it with the `text_generation.tools` section added and enable the tools you need
+
+💡 **Note**: These tools run on OpenAI's infrastructure and may incur additional costs. Web search results include citations that are incorporated into the response.
+
+
 #### On-demand involvement
 
 In the following 2 cases, it's useful to involve the bot in conversations on-demand: