v0.0.3: add built-in web tools

Add no-key web_search and web_fetch tools.
Fetch pages with net/http and parse HTML content.
Document built-in web capabilities.

README.md

@@ -11,6 +11,7 @@ model/provider switching, and local tools.
 - Multiple providers from `~/.agentu/config.yaml`.
 - Session-only provider, model, and thinking-level switching.
 - Read-only project tools enabled by default.
+- Built-in web search and URL fetching.
 - `--yolo` mode for file writes and shell execution.
 
 ## Quick Start
@@ -58,6 +59,10 @@ agent:
   tool_timeout: 30s
 ```
 
+Web tools are enabled by default with a built-in no-key backend. agentu exposes
+`web_search` for current or external web information and `web_fetch` for reading
+a known URL.
+
 Provider names are the keys under `providers`. At startup, agentu selects the
 first provider by name. Use `/model provider <name>` to switch providers for the
 current session.
@@ -112,6 +117,11 @@ Read-only tools are available by default:
 - `file_list`
 - `file_search`
 
+Web tools are also available in read-only mode:
+
+- `web_search`
+- `web_fetch`
+
 `--yolo` additionally enables:
 
 - `file_write`