feat: unify web tool config under WebToolsConfig + add web tool toggle controls

- Rename WebSearchConfig references to the new WebToolsConfig root struct that wraps both search config and global proxy settings
- Add 'enable' flag to WebToolsConfig to allow fully disabling all web-related tools (WebSearch, WebFetch) at runtime
- Update AgentLoop and SubagentManager to receive the full web config object instead of separate web_search_config/web_proxy parameters
- Update CLI command initialization to pass the consolidated web config struct instead of split fields
- Change default web search provider from brave to duckduckgo for better out-of-the-box usability (no API key required)

nanobot/agent/subagent.py

@@ -17,7 +17,7 @@ from nanobot.agent.tools.shell import ExecTool
 from nanobot.agent.tools.web import WebFetchTool, WebSearchTool
 from nanobot.bus.events import InboundMessage
 from nanobot.bus.queue import MessageBus
-from nanobot.config.schema import ExecToolConfig
+from nanobot.config.schema import ExecToolConfig, WebToolsConfig
 from nanobot.providers.base import LLMProvider
 
 
@@ -30,8 +30,7 @@ class SubagentManager:
         workspace: Path,
         bus: MessageBus,
         model: str | None = None,
-        web_search_config: "WebSearchConfig | None" = None,
-        web_proxy: str | None = None,
+        web_config: "WebToolsConfig | None" = None,
         exec_config: "ExecToolConfig | None" = None,
         restrict_to_workspace: bool = False,
     ):
@@ -41,8 +40,7 @@ class SubagentManager:
         self.workspace = workspace
         self.bus = bus
         self.model = model or provider.get_default_model()
-        self.web_search_config = web_search_config or WebSearchConfig()
-        self.web_proxy = web_proxy
+        self.web_config = web_config or WebToolsConfig()
         self.exec_config = exec_config or ExecToolConfig()
         self.restrict_to_workspace = restrict_to_workspace
         self.runner = AgentRunner(provider)
@@ -100,14 +98,16 @@ class SubagentManager:
             tools.register(WriteFileTool(workspace=self.workspace, allowed_dir=allowed_dir))
             tools.register(EditFileTool(workspace=self.workspace, allowed_dir=allowed_dir))
             tools.register(ListDirTool(workspace=self.workspace, allowed_dir=allowed_dir))
-            tools.register(ExecTool(
-                working_dir=str(self.workspace),
-                timeout=self.exec_config.timeout,
-                restrict_to_workspace=self.restrict_to_workspace,
-                path_append=self.exec_config.path_append,
-            ))
-            tools.register(WebSearchTool(config=self.web_search_config, proxy=self.web_proxy))
-            tools.register(WebFetchTool(proxy=self.web_proxy))
+            if self.exec_config.enable:
+                tools.register(ExecTool(
+                    working_dir=str(self.workspace),
+                    timeout=self.exec_config.timeout,
+                    restrict_to_workspace=self.restrict_to_workspace,
+                    path_append=self.exec_config.path_append,
+                ))
+            if self.web_config.enable:
+                tools.register(WebSearchTool(config=self.web_config.search, proxy=self.web_config.proxy))
+                tools.register(WebFetchTool(proxy=self.web_config.proxy))
             
             system_prompt = self._build_subagent_prompt()
             messages: list[dict[str, Any]] = [